Polyurethanes and graft copolymers based on polyurethane, and their use for producing coating materials, adhesives, and sealing compounds

ABSTRACT

A hydrophilic or hydrophobic polyurethane having at least one pendant and/or at least one terminal olefinically unsaturated group, in which  
     1. the pendant olefinically unsaturated group  
     1.1 is attached to a cycloaliphatic group which represents a link in the polymer main chain, or  
     1.2 is present as a double bond in a cycloolefinic group which constitutes a link in the polymer main chain, and  
     2. the terminal olefinically unsaturated group  
     2.1 is attached to a cycloaliphatic group which forms an endgroup of the polymer main chain, or  
     2.2 is present as a double bond in a cycloolefinic structure which forms an endgroup of the polymer main chain;  
     graft copolymers of polyurethane with olefinically unsaturated monomers, processes for preparing the polyurethane and the graft copolymers, and their use to prepare coating materials, adhesives, and sealing compounds.

[0001] The present invention relates to novel polyurethanes and to novelpolyurethane-based graft copolymers. The present invention furtherrelates to novel processes for preparing polyurethanes andpolyurethane-based graft copolymers. The present invention furtherrelates to the use of the novel polyurethanes and of the novelpolyurethane-based graft copolymers to prepare coating materials,adhesives, and sealing compounds. Furthermore, the present inventionrelates to novel coating materials, adhesives, and sealing compounds,especially aqueous coating materials, adhesives, and sealing compounds.The present invention relates not least to novel coats, adhesive films,and seals obtainable from the novel, especially aqueous, coatingmaterials, adhesives, and sealing compounds. In particular the presentinvention relates to single-coat or multicoat decorative and/orprotective coating systems, especially multicoat color and/or effectcoating systems.

[0002] Polyurethane-based graft copolymers are known. They are normallyprepared by the graft copolymerization of olefinically unsaturatedmonomers in the aqueous dispersion of a hydrophilic or hydrophobicpolyurethane whose polymer chain includes terminal and/or lateral,olefinically unsaturated groups. Groups of this kind may be incorporated

[0003] into the polyurethane chain by way of maleic acid or fumaric acidand/or their esters,

[0004] laterally to the polyurethane chain by way of compounds havingtwo isocyanate-reactive groups and at least one olefinically unsaturatedgroup or by way of compounds having two isocyanate groups and at leastone olefinically unsaturated group,

[0005] terminally to the polyurethane chain by way of compounds havingone isocyanate-reactive group and at least one olefinically unsaturatedgroup or by way of compounds having one isocyanate group and at leastone olefinically unsaturated group, or

[0006] by way of anhydrides of alpha,beta-unsaturated carboxylic acids.

[0007] By way of example, reference is made to patent applications andpatents DE 197 22 862 C2, DE 196 45 761 A1, EP 0 401 565 A1, EP 0 522420 A1, EP 0 522 419 A2, EP 0 755 946 A1, EP 0 608 021 A1, EP 0 708 788A1 or EP 0 730 613 A1, and also German Patent Applications DE 199 53446.2 or DE 199 53 203.6, unpublished at the priority date of thepresent specification.

[0008] Moreover, German Patent Applications DE 199 48 004.4-44,unpublished at the priority date of the present specification, describesexternally crosslinking polyurethanes containing pendant, i.e., lateral,ethenylarylene groups as grafting sites, and the correspondingexternally crosslinking graft copolymers.

[0009] Furthermore, German Patent Application DE 199 53 445.4-44,unpublished at the priority date of the present specification, describesthe corresponding self-crosslinking polyurethanes and theirself-crosslinking graft copolymers.

[0010] In the context of the present invention, the property ofhydrophilicity denotes the constitutional property of a molecule orfunctional group to penetrate into the aqueous phase or to remaintherein. Accordingly, in the context of the present invention, theproperty of hydrophobicity denotes the constitutional property of amolecule or functional group to behave exophilically with respect towater, i.e., to tend not to penetrate into water or to tend to departthe aqueous phase. For further details, reference is made to RömppLexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, New York,1998, “Hydrophilicity”, “Hydrophobicity”, pages 294 and 295.

[0011] In the context of the present invention, the term“self-crosslinking” denotes the capacity of a binder to enter intocrosslinking reactions of itself. A prerequisite for this is thepresence in the polyurethanes and the graft copolymers of complementaryreactive functional groups which react with one another and so lead tocrosslinking. Alternatively, the polyurethanes and graft copolymerscontain reactive functional groups which react “with themselves”. Theterm externally crosslinking, on the other hand, is used to refer tothose polyurethanes and graft copolymers in which one variety of thecomplementary reactive functional groups is present in the polyurethanesand graft copolymers and the other variety is present in a hardener,curing agent or crosslinking agent. For further details, reference ismade to Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag,Stuttgart, New York, 1998, “Curing”, pages 274 to 276, especially page275, bottom.

[0012] The known polyurethane-based graft copolymers are used especiallyfor the preparation of waterborne coating materials. The knownwaterborne coating materials serve primarily to produce color and/oreffect basecoats in multicoat coating systems by the wet-on-wettechnique, as are described, for example, in the patents and patentapplications recited above.

[0013] Nevertheless, the preparation of the known polyurethane-basedgraft copolymers may cause problems.

[0014] For instance, lateral and/or terminal allyl groups are oftenincorporated as grafting centers. However, the reactivity of the allylgroups is comparatively low. If the more reactive acrylate ormethacrylate groups are used instead, gelling of the polyurethanes mayoccur before or during the graft copolymerization.

[0015] In some cases it is possible, not least, for the amount ofolefinically unsaturated groups in the polyurethanes to prove too lowfor complete grafting, with the consequence that a large proportion ofthe monomers intended for grafting on forms separate homopolymers and/orcopolymers alongside the polyurethane, which may adversely affect theperformance properties of the graft copolymers and of the coatingmaterials, adhesives, and sealing compounds prepared with them. Thisdisadvantage cannot be easily eliminated by raising the double-bondfraction in the polyurethanes to be grafted, since to do so isdetrimental to other important performance properties of thepolyurethanes.

[0016] For instance, in the case of overcoating with powder slurryclearcoats, the clearcoat may crack during baking and/or may undergodelamination, especially after the water jet test. Moreover, poppingmarks may appear.

[0017] It is an object of the present invention to provide newhydrophilic and hydrophobic olefinically unsaturated polyurethanes whichhave not only terminal but also pendant olefinically unsaturated groups,which may be prepared simply and purposively without the risk of productdamage, and which constitute excellent grafting bases for olefinicallyunsaturated monomers.

[0018] A further object of the present invention is to find a newprocess for preparing olefinically unsaturated polyurethanes whichsimply, purposively and without the risk of product damage provideshydrophilic or hydrophobic polyurethanes having pendant and/or terminalolefinically unsaturated groups.

[0019] Another object of the present invention is to find new graftcopolymers in the form of primary dispersions or secondary dispersionswhich may be prepared simply, purposively and without the risk ofproduct damage.

[0020] The novel graft copolymers should be physically curing, thermallyself-crosslinking or externally crosslinking, or curable thermally andwith actinic radiation (dual cure).

[0021] In the context of the present invention, the term “physicalcuring” means the curing of a polyurethane or of a graft copolymer byfilming, linking taking place within a coating by way of formation ofloops of the polymer molecules of the binders (regarding the term cf.Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, NewYork, 1998, “Binders”, pages 73 and 74). Alternatively, filming takesplace by the coalescence of polymer particles (cf. Römpp Lexikon Lackeund Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998,“Curing”, pages 274 and 275). Normally, no crosslinking agents arerequired for this purpose. If desired, physical curing may be assistedby atmospheric oxygen, heat, or exposure to actinic radiation.

[0022] In the context of the present invention, actinic radiation iselectromagnetic radiation, such as visible light, UV radiation orX-radiation, especially UV radiation, and corpuscular radiation such aselectron beams.

[0023] Yet another object of the present invention is to provide newaqueous and nonaqueous, physically curing, thermally self-crosslinkingor externally crosslinking, or heat- and actinic-curing,polyurethane-based coating materials, adhesives and sealing compoundshaving very good performance properties. In particular the intention isto provide new coating materials, especially new aqueous coatingmaterials, specifically new aqueous basecoats, from which thedisadvantages of the prior art are now absent and which instead areoutstandingly suitable for application by the wet-on-wet technique. Inthis context, even with the use of powder clearcoat slurries, thereshould be no cracking (mudcracking) in the clearcoats, delamination ofthe clearcoats after the water jet test, or popping marks or pinholes.The new coating materials should possess very good storage stability,outstanding application properties, such as very good leveling and verylittle tendency to run, even at high coat thicknesses, an outstandingoverall visual appearance, and high chemical resistance and weatheringstability. Moreover, the new coating materials, adhesives and sealingcompounds should have these advantageous properties both asone-component systems and as two-component or multicomponent systems.

[0024] In the context of the present invention, two-component ormulticomponent systems are coating materials, adhesives and sealingcompounds whose crosslinking agent, owing to its high reactivity, has tobe stored separately from other constituents of the coating materials,adhesives and sealing compounds prior to application.

[0025] Accordingly, we have found the novel hydrophilic or hydrophobicpolyurethane having at least one pendant and/or at least one terminalolefinically unsaturated group, in which

[0026] 1. the pendant olefinically unsaturated group

[0027] 1.1 is attached to a cycloaliphatic group which represents a linkin the polymer main chain, or

[0028] 1.2 is present as a double bond in a cycloolefinic structurewhich represents a link in the polymer main chain, and

[0029] 2. the terminal olefinically unsaturated group

[0030] 2.1 is attached to a cycloaliphatic group which forms an endgroup of the polymer main chain, or

[0031] 2.2 is present as a double bond in a cycloolefinic structurewhich forms an end group of the polymer main chain.

[0032] In the text below, the novel hydrophilic or hydrophobicpolyurethane having at least one pendant and/or at least one terminalolefinically unsaturated group is referred to as the “polyurethane ofthe invention”.

[0033] We have further found the novel graft copolymer preparable by(co)polymerizing at least one olefinically unsaturated monomer in thepresence of the polyurethane of the invention.

[0034] In the text below, the novel graft copolymer based on thepolyurethane of the invention is referred to as the “graft copolymer ofthe invention”.

[0035] We have additionally found the novel adhesives, sealing compoundsand coating materials, in particular coating materials, especiallyaqueous coating materials, specifically aqueous basecoats, whichcomprise at least one polyurethane of the invention and/or at least onegraft copolymer of the invention and which are referred to below asadhesives, sealing compounds and coating materials of the invention.

[0036] Further subjects of the invention will emerge from thedescription.

[0037] In the light of the prior art it was surprising, andunforeseeable for the skilled worker, that the complex problem on whichthe present invention was based, could be solved with the aid of thepolyurethanes of the invention and/or of the graft copolymers of theinvention. A particular surprise was that the polyurethanes of theinvention and the graft copolymers of the invention can be preparedsimply and purposively without damage to the products of the invention.A further surprise was the extremely broad usefulness of thepolyurethanes of the invention and of the graft copolymers of theinvention. It was totally unforeseeable that the graft copolymers of theinvention, in particular, give aqueous basecoats which may be processedtogether with powder clearcoat slurries by the wet-on-wet technique toform outstanding multicoat color and/or effect coating systems withoutany cracking (mudcracking) in the clearcoats, delamination of theclearcoats after the water jet test, or popping marks or pinholes.

[0038] The polyurethane of the invention comprises at least one pendantand/or at least one terminal olefinically unsaturated group.Alternatively expressed, the polyurethane of the invention comprises atleast one pendant, at least one terminal, or at least one pendant and atleast one terminal olefinically unsaturated group. In this context, thepolyurethanes of the invention which comprise at least one pendantolefinically unsaturated group afford particular advantages and aretherefore particularly preferred in accordance with the invention.

[0039] The polyurethane of the invention is hydrophobic or hydrophilicin the abovementioned sense. In terms of their use to prepare the graftcopolymers of the invention, the hydrophilic polyurethanes of theinvention afford advantages and are therefore used with preference.

[0040] The pendant olefinically unsaturated group either is attached toa cycloaliphatic group which represents a link in the polymer main chainor is present as a double bond in a cycloolefinic group which likewiserepresents a link in the polymer main chain.

[0041] The terminal olefinically unsaturated group is attached to acycloaliphatic group which forms an end group of the polymer main chain,or it is present as a double bond in a cycloolefinic group whichlikewise forms an end group of the polymer main chain.

[0042] In accordance with the invention, two or more olefinicallyunsaturated groups may be attached to one cycloaliphatic group. It is ofadvantage, however, if only one olefinically unsaturated group isattached to one cycloaliphatic group.

[0043] Suitable olefinically unsaturated groups are, fundamentally, allgroups containing at least one, especially one, double bond. In thecontext of the present invention, a double bond is a carbon-carbondouble bond. Examples of highly suitable olefinically unsaturated groupsare (meth)acrylate, ethacrylate, crotonate, cinnamate, vinyl ether,vinyl ester, vinyl, dicyclopentadienyl, norbornenyl, isoprenyl,isopropenyl, allyl and/or butenyl groups; dicyclopentadienyl ether,norbornenyl ether, isoprenyl ether, isopropenyl ether, allyl ether orbutenyl ether groups; and/or dicyclopentadienyl ester, norbornenylester, isoprenyl ester, isopropenyl ester, allyl ester and/or butenylester groups. Of these, the vinyl groups are particularly advantageousand are therefore used with particular preference.

[0044] Similarly, two or more double bonds may be present in onecycloolefinic group. It is of advantage if there is only one double bondper cycloolefinic group.

[0045] In a polyurethane of the invention, both the above-describedcycloaliphatic groups and the above-described cycloolefinic groups maybe present.

[0046] In accordance with the invention, the cycloaliphatic groups areof advantage and are therefore used with preference.

[0047] The cycloaliphatic groups may be derived from any desiredcycloaliphatics. In accordance with the invention it is of advantage ifthey are derived from cycloaliphatics having 4 to 12 carbon atoms in themolecule.

[0048] The cycloolefinic groups, similarly, may be derived from anydesired cycloolefins. In accordance with the invention it is ofadvantage if they are derived from cycloolefins having 4 to 12 carbonatoms in the molecule.

[0049] Examples of highly suitable cycloaliphatics are cyclobutane,cyclopentane, cyclohexane, cycloheptane, cycloctane, norbornane,bicyclo[2.2.2]octane, decalin, hydroindane, dicylcopentene,tricyclodecane or adamantane, but especially cyclohexane.

[0050] Examples of highly suitable cycloolefins are cyclopentene,cyclohexene, cycloheptene, cyclooctene, norbornene, bicyclo[2.2.2]octeneor dicylclopentene.

[0051] The polyurethane of the invention may be prepared by a very widevariety of methods of polymer chemistry. It is of advantage, however, toprepare the polyurethane of the invention by reacting

[0052] (i) at least one polyurethane prepolymer having at least one freeisocyanate group in the molecule with

[0053] (ii) at least one cycloaliphatic having at least one, especiallyone, olefinically unsaturated group and having at least two, especiallytwo, isocyanate-reactive groups in the molecule, and/or with

[0054] (iii) at least one cycloolefin having at least one, especiallyone, double bond and having at least two, especially two,isocyanate-reactive groups in the molecule.

[0055] If an excess of isocyanate groups over the isocyanate-reactivegroups is employed in the reaction, the cycloaliphatics (ii) and/or thecycloolefins (iii) are incorporated predominantly or exclusively intothe polymer main chain. If, on the other hand, an excess ofisocyanate-reactive groups over the isocyanate groups is employed, thecycloaliphatics (ii) and/or the cycloolefins (iii) are convertedpredominantly or exclusively to end groups. The skilled worker,therefore, is able easily to control the reaction so as to obtainpolyurethanes of the invention having the desired structures.

[0056] The cycloaliphatics (ii) or the cycloolefins (iii) comprise atleast two isocyanate-reactive groups. In other words, they may containtwo, three, four or more isocyanate-reactive groups in the molecule. Itis also possible to use mixtures of cycloaliphatics (ii) and/orcycloolefins (iii) each having a different number of isocyanate-reactivegroups in the molecule. Thus it is possible, for example, to usemixtures of cycloaliphatics (ii) and/or cycloolefins (iii) having twoand cycloaliphatics (ii) and/or cycloolefins (iii) having threeisocyanate-reactive groups in the molecule. By this means it is possibleto prepare branched polyurethanes of the invention in a simple manner.It is advantageous in this context to use the compounds (ii) and/or(iii) of higher functionality in minor amounts in order to preventgelling of the reaction mixture. In the great majority of cases,however, only bifunctional cycloaliphatics (ii) and/or cycloolefins(iii) are used.

[0057] Examples of suitable isocyanate-reactive groups are and hydroxyl,thiol and/or primary and/or secondary amino groups. In accordance withthe invention, hydroxyl groups are of advantage and are therefore usedwith preference.

[0058] Examples of suitable olefinically unsaturated groups for thecycloaliphatics (ii) are those described above, of which the vinylgroups is used with particular preference.

[0059] Examples of highly suitable cycloaliphatics (ii) are thepositionally isomeric vinyl-substituted polyhydroxy derivatives,especially the dihydroxy derivatives, of cyclobutane, cyclopentane,cyclohexane, cycloheptane, cycloctane, norbornane, bicyclo[2.2.2]octane,decalin, hydroindane, dicylcopentane, tricylclodecane or adamantane.

[0060] Examples of highly suitable cycloolefins (iii) are thepositionally isomeric polyhydroxy derivatives, especially the dihydroxyderivatives, of cyclopentene, cyclohexene, cycloheptene, cyclooctene,norbornene, bicyclo[2.2.2]octene or dicylclopentene.

[0061] In accordance with the invention, the positionally isomericvinylcyclohexanadiols (ii) 1-vinylcyclohexane-2,6-, -3,6-, -4,6-, -2,3-,-3,4and/or -3,5-diol are very particularly advantageous and aretherefore used with very particular preference. The positionallyisomeric vinylcyclohexanediols (ii) are customary and known compoundsand are obtained as mixtures in industrial syntheses. In the text below,they are referred to for the sake of brevity as “vinylcyclohexanediol”.

[0062] The polyurethane prepolymer (i) is of linear, branched or comb,but especially linear, construction. In this context the linearpolyurethane prepolymer (i) includes preferably two free isocyanategroups, especially two terminal free isocyanate groups. The branched orcomb-constructed polyurethane prepolymers (i) include preferably atleast two, in particular more than two, free isocyanate groups, terminalfree isocyanate groups being preferred.

[0063] In terms of method, the preparation of the polyurethaneprepolymers (i) for use in accordance with the invention has no specialfeatures but instead takes place, for example, as described in patent DE197 22 862 C1 or in patent applications DE 196 45 761 A1, EP 0 522 419A1 or EP 0 522 420 A1, by reaction of a polyol, especially a diol, withat least one polyisocyanate, especially a diisocyanate, the isocyanatecomponent being employed in a molar excess.

[0064] For the preparation of the polyurethane prepolymers (i) it ispreferred to use diisocyanates and also, if desired, in minor amounts,polyisocyanates, for the purpose of introducing branches. In the contextof the present invention, minor amounts are amounts which do not causegelling of the polyurethane prepolymers (i) during their preparation.This may also be prevented by using small amounts of monoisocyanates.

[0065] Examples of suitable diisocyanates are isophorone diisocyanate(i.e., 5-isocyanato-1-isocyanatomethyl-1,3,3-trimethylcyclohexane),5-isocyanato-1(2-isocyanatoeth-1-yl)-1,3,3-trimethylcyclohexane,5-isocyanato-1-(3-isocyanatoprop-1-yl)-1,3,3-trimethylcyclohexane,5-isocyanato-(4-isocyanatobut-1-yl)-1,3,3-trimethylcyclohexane,1-isocyanato-2-(3-isocyanatoprop-1-yl)cyclohexane,1-isocyanato-2-(3-isocyanatoeth-1-yl)cyclohexane,1-isocyanato-2-(4-isocyanatobut-1-yl)cyclohexane,1,2-diisocyanatocyclobutane, 1,3-diisocyanatocyclobutane,1,2-diisocyanatocyclopentane, 1,3-diisocyanatocyclopentane,1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane,1,4-diisocyanatocyclohexane, dicyclohexylmethane 2,4′-diisocyanate,trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylenediisocyanate, hexamethylene diisocyanate, ethylethylene diisocyanate,trimethylhexane diisocyanate, heptanemethylene diisocyanate ordiisocyanates derived from dimeric fatty acids, as marketed under thecommercial designation DDI 1410 by the company Henkel and described inpatents WO 97/49745 and WO 97/49747, especially2-heptyl-3,4-bis(9-isocyanatononyl)-1-pentylcyclohexane, or 1,2-, 1,4-or 1,3-bis(isocyanatomethyl)cyclohexane, 1,2-, 1,4- or1,3-bis(2-isocyanatoeth-1-yl)cyclohexane,1,3-bis(3-isocyanatoprop-1-yl)cyclohexane, 1,2-, 1,4- or1,3-bis(4-isocyanatobut-1-yl)cyclohexane, liquidbis(4-isocyanatocyclohexyl)methane with a trans/trans content of up to30% by weight, preferably 25% by weight, and in particular 20% byweight, as is described [lacuna] patents DE 44 14 032 A1, GB 1 220 717A, DE 16 18 795 A1 or DE 17 93 785 A1; tolylene diisocyanate, xylylenediisocyanate, bisphenylene diisocyanate, naphthylene diisocyanate ordiphenylmethane diisocyanate.

[0066] Examples of suitable polyisocyanates are the isocyanurates of thediisocyanates described above.

[0067] Examples of highly suitable monoisocyanates are phenylisocyanate, cyclohexyl isocyanate or stearyl isocyanate.

[0068] The polyurethane prepolymers (i) are also prepared using

[0069] saturated and unsaturated polyols of relatively high and lowmolecular mass, especially diols and, in minor amounts, triols for thepurpose of introducing branches, and also, if desired,

[0070] compounds which introduce hydrophilic functional groups,

[0071] polyamines, and

[0072] amino alcohols.

[0073] Examples of suitable polyols are saturated or olefinicallyunsaturated polyester polyols which are prepared by reacting

[0074] unsulfonated or sulfonated saturated and/or unsaturatedpolycarboxylic acids or their esterifiable derivatives, alone ortogether with monocarboxylic acids, and

[0075] saturated and/or unsaturated polyols, alone or together withmonools.

[0076] Examples of suitable polycarboxylic acids are aromatic, aliphaticand cycloaliphatic polycarboxylic acids. Preference is given to the useof aromatic and/or aliphatic polycarboxylic acids.

[0077] Examples of suitable aromatic polycarboxylic acids are phthalicacid, isophthalic acid, terephthalic acid, phthalic, isophthalic orterephthalic acid monosulfonate, or halophthalic acids, such astetrachlorophthalic or tetrabromophthalic acid, among which isophthalicacid is advantageous and is therefore used with preference.

[0078] Examples of suitable acyclic aliphatic or unsaturatedpolycarboxylic acids are oxalic acid, malonic acid, succinic acid,glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid,sebacic acid, undecanedicarboxylic acid or dodecanedicarboxylic acid, ormaleic acid, fumaric acid or itaconic acid, of which adipic acid,glutaric acid, azelaic acid, sebacic acid, dimeric fatty acids andmaleic acid are advantageous and are therefore used with preference.

[0079] Examples of suitable cycloaliphatic and cyclic unsaturatedpolycarboxylic acids are 1,2-cyclobutanedicarboxylic acid,1,3-cyclobutanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid,1,3-cyclopentanedicarboxylic acid, hexahydrophthalic acid,1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid,4-methylhexahydrophthalic acid, tricyclodecanedicarboxylic acid,tetrahydrophthalic acid or 4-methyltetrahydrophthalic acid. Thesedicarboxylic acids may be used both in their cis and in their trans formand also as a mixture of both forms.

[0080] Further examples of suitable polycarboxylic acids are polymericfatty acids, especially those having a dimer content of more than 90% byweight, which are also known as dimeric fatty acids.

[0081] Also suitable are the esterifiable derivatives of theabovementioned polycarboxylic acids, such as their monoesters orpolyesters with aliphatic alcohols having 1 to 4 carbon atoms or hydroxyalcohols having 1 to 4 carbon atoms, for example. It is also possible touse the anhydrides of the abovementioned polycarboxylic acids, wherethey exist.

[0082] Together with the polycarboxylic acids it is also possible ifdesired to use monocarboxylic acids, such as, for example, benzoic acid,tert-butylbenzoic acid, lauric acid isononanoic acid, fatty acids ofnaturally occurring oils, acrylic acid, methacrylic acid, ethacrylicacid or crotonic acid. The preferred monocarboxylic acid used isisononanoic acid.

[0083] Examples of suitable polyols are diols and triols, especiallydiols. Normally, triols are used alongside the diols in minor amounts inorder to introduce branches into the polyester polyols. In the contextof the present invention, minor amounts are amounts which do not causegelling of the polyester polyols during their preparation.

[0084] Suitable diols are ethylene glycol, 1,2- or 1,3-propanediol,1,2-, 1,3- or 1,4-butanediol, 1,2-, 1,3-, 1,4- or 1,5-pentanediol, 1,2-,1,3-, 1,4-, 1,5- or 1,6-hexanediol, neopentyl hydroxypivalate, neopentylglycol, diethylene glycol, 1,2-, 1,3- or 1,4-cyclohexanediol, 1,2-, 1,3-or 1,4-cyclohexanedimethanol, trimethylpentanediol,ethylbutylpropanediol or the positionally isomeric diethyloctanediols.These diols may also be used per se for the preparation of thepolyurethanes (A) for use in accordance with the invention.

[0085] Further examples of suitable diols are diols of the formula I orII:

[0086] where R and R¹ are each an identical or different radical and arean alkyl radical having 1 to 18 carbon atoms, an aryl radical or acycloaliphatic radical, with the proviso that R and/or R¹ must not bemethyl;

[0087] where R², R³, R⁴ and R⁶ are each identical or different radicalsand are an alkyl radical having 1 to 6 carbon atoms, a cycloalkylradical or an aryl radical and R⁴ is an alkanediyl radical having 1 to 6carbon atoms, an arylene radical or an unsaturated alkenediyl radicalhaving 1 to 6 carbon atoms, and n is either 0 or 1.

[0088] Suitable diols I of the general formula I are all propanediols inwhich either R or R¹, or R and R¹ is or are not methyl, such as, forexample, 2-butyl-2-ethyl-1,3-propanediol,2-butyl-2-methyl-1,3-propanediol, 2-phenyl-2-methyl-1,3-propanediol,2-propyl-2-ethyl-1,3-propanediol, 2-di-tert-butyl-1,3-propanediol,2-butyl-2-propyl-1,3-propanediol,1-dihydroxymethylbicyclo[2.2.1]heptane, 2,2-diethyl-1,3-propanediol,2,2-dipropyl-1,3-propanediol or 2-cyclohexyl-2-methyl-1,3-propanediol,et cetera.

[0089] Examples of diols II of the general formula II that may be usedare 2,5-dimethyl-2,5-hexanediol, 2,5diethyl-2,5-hexanediol,2-ethyl-5-methyl-2,5-hexanediol, 2,4-dimethyl-2,4-pentanediol,2,3-dimethyl-2,3-butanediol, 1,4-(2′-hydroxypropyl)benzene and1,3-(2′hydroxypropyl)benzene.

[0090] Of these diols, hexanediol and neopentyl glycol are particularlyadvantageous and are therefore used with particular preference.

[0091] The abovementioned diols may also be used per se to prepare thepolyurethane prepolymers (i).

[0092] Examples of suitable triols are trimethylolethane,trimethylolpropane or glycerol, especially trimethylolpropane.

[0093] The abovementioned triols may also be used per se to prepare thepolyurethane prepolymers (i) (cf. EP 0 339 433 A1).

[0094] If desired, minor amounts of monools may also be used. Examplesof suitable monools are alcohols or phenols such as ethanol, propanol,n-butanol, sec-butanol, tert-butanol, amyl alcohols, hexanols, fattyalcohols, allyl alcohol, or phenol.

[0095] The polyester polyols may be prepared in the presence of smallAmounts of a suitable solvent as entrainer. Examples of entrainers usedare aromatic hydrocarbons, such as especially xylene and(cyclo)aliphatic hydrocarbons, e.g., cyclohexane or methylcyclohexane.

[0096] Further examples of suitable polyols are polyester diols whichare obtained by reacting a lactone with a diol. They are notable for thepresence of terminal hydroxyl groups and repeating polyester fractionsof the formula —(—CO—(CHR⁷)_(m)—CH₂—O—)—. Here, the index m ispreferably from 4 to 6 and the substituent R⁷ is hydrogen or an alkyl,cycloalkyl, or alkoxy radical. No substituent contains more than 12carbon atoms. The total number of carbon atoms in the substituent doesnot exceed 12 per lactone ring. Examples are hydroxycaproic acid,hydroxybutyric acid, hydroxydecanoic acid, and/or hydroxystearic acid.

[0097] Preferred for the preparation of the polyester diols is theunsubstituted ###-caprolactone, where m is 4 and all substituents R⁷ arehydrogen. The reaction with lactone is started by low molecular masspolyols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, ordimethylolcyclohexane. It is also possible, however, to react otherreaction components, such as ethylenediamine, alkyldialkanolamines, orelse urea, with caprolactone. Other suitable diols of relatively highmolecular mass are polylactam diols, which are prepared by reacting, forexample, ###-caprolactam with low molecular mass diols.

[0098] Further examples of suitable polyols include polyether polyols,especially those having a number-average molecular weight of from 400 to5000, in particular from 400 to 3000. Examples of highly suitablepolyether diols are polyether diols of the general formulaH—(—O—(CHR⁸)_(o)-)_(p)OH, where the substituent R⁸ is hydrogen or alower, unsubstituted or substitued alkyl radical, the index o is from 2to 6, preferably from 3 to 4, and the index p is from 2 to 100,preferably from 5 to 50. Especially suitable examples are linear orbranched polyether diols such as poly(oxyethylene) glycols,poly(oxypropylene) glycols, and poly(oxybutylene) glycols.

[0099] By means of the polyether diols it is possible to introducenonionic hydrophilic functional groups into the main chain(s) of thepolyurethane prepolymers (i).

[0100] Hydrophilic polyurethane prepolymers (i) comprise alternatively

[0101] hydrophilic functional groups convertible to cations byneutralizing agents and/or quaternizing agents, and/or cationic groups,

[0102] or

[0103] functional groups convertible to anions by neutralizing agents,and/or anionic groups,

[0104] and/or

[0105] nonionic hydrophilic groups.

[0106] Examples of suitable functional groups for use in accordance withthe invention and convertible to cations by neutralizing agents and/orquaternizing agents are primary, secondary or tertiary amino groups,secondary sulfide groups or tertiary phoshine groups, especiallytertiary amino groups or secondary sulfide groups.

[0107] Examples of suitable cationic groups for use in accordance withthe invention are primary, secondary, tertiary or quaternary ammoniumgroups, tertiary sulfonium groups or quaternary phosphonium groups,preferably quaternary ammonium groups or tertiary sulfonium groups, butespecially tertiary ammonium groups.

[0108] Examples of suitable functional groups for use in accordance withthe invention and convertible to anions by neutralizing agents arecarboxylic acid, sulfonic acid or phosphonic acid groups, especiallycarboxylic acid groups.

[0109] Examples of suitable anionic groups for use in accordance withthe invention are carboxylate, sulfonate or phosphonate groups,especially carboxylate groups.

[0110] Examples of suitable neutralizing agents for functional groupsconvertible to cations are organic and inorganic acids such as formicacid, acetic acid, lactic acid, dimethylolpropionic acid, citric acid,sulfuric acid, hydrochloric acid, and phosphoric acid.

[0111] Examples of suitable neutralizing agents for functional groupsconvertible to anions are ammonia or amines, such as trimethylamine,triethylamine, tributylamine, dimethylaniline, diethylaniline,triphenylamine, dimethylethanolamine, diethylethanolamine,methyldiethanolamine, 2-aminomethylpropanol, dimethylisopropylamine,dimethylisopropanolamine or triethanolamine, for example. Neutralizationmay take place in organic phase or in aqueous phase. Preferredneutralizing agents used are dimethylethanolamine and/or triethylamine.

[0112] The introduction of hydrophilic functional (potential) cationicgroups into the polyurethane prepolymers (i) takes place by way of theincorporation of compounds which contain in the molecule at least one,especially two, isocyanate-reactive groups and at least one groupcapable of forming cations; the amount to be used may be calculated fromthe target amine number.

[0113] Suitable isocyanate-reactive functional groups are thosedescribed above. Examples of suitable compounds of this kind are2,2-dimethylolethyl- or -propylamine blocked with a ketone, theresultant ketoxime group being hydrolyzed again prior to the formationof the cationic group, or N,N-dimethyl-, N,N-diethyl- orN-methyl-N-ethyl-2,2-dimethylolethyl- or -propylamine.

[0114] The introduction of hydrophilic functional (potentially) anionicgroups into the polyurethane prepolymers (i) takes place by way of theincorporation of compounds which contain in the molecule at least oneisocyanate-reactive group and at least one group capable of forminganions; the amount to be used may be calculated from the target acidnumber.

[0115] Examples of suitable compounds of this kind are those containingtwo isocyanate-reactive groups in the molecule. Here again, suitableisocyanate-reactive groups are those described above. Accordingly it ispossible, for example, to use alkanoic acids having two substituents onthe ### carbon atom. The substituent may be a hydroxyl group, an alkylgroup, or, preferably, an alkylol group. These alkanoic acids have atleast one, generally from 1 to 3, carboxyl groups in the molecule. Theyhave 2 to about 25, preferably 3 to 10, carbon atoms. Examples ofsuitable alkanoic acids are dihydroxypropionic acid, dihydroxysuccinicacid, and dihydroxybenzoic acid. A particularly preferred group ofalkanoic acids are the ###,###-dimethylolalkanoic acids of the generalformula R⁹-C(CH₂OH)₂COOH, R⁹ being a hydrogen atom or an alkyl grouphaving up to about 20 carbon atoms. Examples of especially suitablealkanoic acids are 2,2-dimethylolacetic acid, 2,2-dimethylolpropionicacid, 2,2-dimenthylolbutyric acid, and 2,2-dimethylolpentanoic acid. Thepreferred dihydroxyalkanoic acid is 2,2-dimethylolpropionic acid.Examples of compounds containing amino groups are ###,###-diaminovalericacid, 3,4-diaminobenzoic acid, 2,4-diaminotoluenesulfonic acid, and2,4-diaminodiphenyl ether sulfonic acid.

[0116] Hydrophilic functional nonionic poly(oxyalkylene) groups may beintroduced as lateral or terminal groups into the polyurethanemolecules. For this purpose it is possible to use not only theabove-described polyether diols but also, for example,alkoxypoly(oxyalkylene) alcohols having the general formulaR¹⁰O—(—CH₂—CHR¹¹—O—)_(r)H, where R¹⁰ is an alkyl radical having 1 to 6carbon atoms, R¹¹ is a hydrogen atom or an alkyl radical having 1 to 6carbon atoms, and the index r is a number between 20 and 75 (cf. patentsEP 0 354 261 A1 or EP 0 424 705 A1).

[0117] The hydrophilic functional groups are to be selected so as torule out the possibility of any disruptive reactions, such as, forinstance, salt formation or crosslinking with the functional groups thatmay be present in the other constituents of the polyurethane of theinvention, of the graft copolymers of the invention, of the coatingmaterial of the invention, of the sealing compound of the invention, orof the adhesive of the invention. The skilled worker will therefore beable to make the selection in a simple manner on the basis of his or herknowledge in the art.

[0118] Of these hydrophilic functional (potentially) ionic groups andthe hydrophilic functional nonionic groups, the (potentially) anionicgroups are advantageous and are therefore used with particularpreference.

[0119] To prepare the hydrophilic and the hydrophobic polyurethaneprepolymers (i) it is possible to use polyamines and amino alcoholswhich bring about an increase in the molecular weight of thepolyurethane prepolymers (i). The essential point in this context isthat the polyamines and amino alcohols are employed in an amount suchthat there are still free isocyanate groups remaining in the molecule.

[0120] Examples of suitable polyamines have at least two primary and/orsecondary amino groups. Polyamines are essentially alkylene polyamineshaving 1 to 40 carbon atoms, preferably about 2 to 15 carbon atoms. Theymay carry substituents which have no hydrogen atoms that are reactivewith isocyanate groups. Examples are nor vamines having a linear orbranched aliphatic, cycloaliphatic or aromatic structure and at leasttwo primary amino groups.

[0121] Diamines include hydrazine, ethylenediamine, propylenediamine,1,4-butylenediamine, piperazine, 1,4-cyclohexyldimethylamine,1,6-hexamethylenediamine, trimethylhexamethylenediamine,menthanediamine, isophoronediamine, 4,4′-diaminodicyclohexylmethane, andaminoethylethanolamine. Preferred diamines are hydrazine, alkyl- orcycloalkyldiamines such as propylenediamine and1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane.

[0122] It is also possible to use polyamines containing more than twoamino groups in the molecule. In these cases, however, it should beensured—for example, by using monoamines as well—that no crosslinkedpolyurethane resins are obtained. Polyamines of this kind which may beused are diethylenetriamine, triethylenetetramine, dipropylenediamine,and dibutylenetriamine. An example of a monoamine is ethylhexylamine(cf. patent EP 0 089 497 B1).

[0123] Examples of suitable amino alcohols are ethanolamine anddiethanolamine.

[0124] Furthermore, to prepare the hydrophilic and hydrophobicpolyurethane prepolymers (i) it is possible to use customary and knowncompounds by means of which olefinically unsaturated groups areintroduced. As is known, such compounds contain at least twoisocyanate-reactive functional groups, especially hydroxyl groups, andat least one olefinically unsaturated group. Examples of suitablecompounds of this kind are known from DE 197 22 862 C1 or patentapplications DE 196 45 761 A1, EP 0 522 419 A1 or EP 0 522 420 A1. Whereused, they are employed in minor amounts, so that the profile ofproperties of the polyurethanes of the invention is determined by theabove-described olefinically unsaturated groups for use in accordancewith the invention.

[0125] The preparation of the polyurethane prepolymers (i) from theconstituents described above has no special features as to method butinstead takes place in accordance with the customary and known methodsof polyurethane chemistry, as known, for example, from the documentsrecited above.

[0126] The preparation of the polyurethanes of the invention from theabove-described polyurethane prepolymers (i) and the above-describedcycloaliphatics (ii) and/or cycloolefins (iii), especially thecycloaliphatics (ii), likewise has no special features as to its methodbut instead takes place in bulk or in an inert organic medium,preferably in an inert organic medium, preference being given to the useof polar organic solvents.

[0127] It is essential that the reaction takes place until the freeisocyanate group content in the reaction mixture stabilizes or untilfree isocyanate groups can no longer be detected. If free isocyanategroups are present after the reaction, they are preferably reacted withat least one polyol, polyamine and/or amino alcohol, as described above.This results in an extension of the chain of the polyurethane of theinvention.

[0128] The amount of cycloaliphatics (ii) and/or cycloolefins (iii)incorporated by reaction in the polyurethanes of the invention may varyvery widely. Preferably it is from 0.01 to 30, more preferably from 0.1to 25, with particular preference from 0.2 to 20, with very particularpreference from 0.25 to 15, and in particular from 0.3 to 10% by weight,based in each case on the polyurethane of the invention.

[0129] The polyurethanes of the invention may be used as such to preparecoating materials, especially paints, and also adhesives and sealingcompounds.

[0130] A particular advantage is that the polyurethanes of theinvention, owing to their double bond content, may be used to preparecoating materials, especially paints, and also adhesives and sealingcompounds, which may be cured with actinic radiation or by dual cure.

[0131] Where the polyurethanes of the invention are hydrophilic, it isof advantage in accordance with the invention to use them in the form ofa dispersion in an aqueous medium The aqueous medium containsessentially water. The aqueous medium may include minor amounts oforganic solvents, neutralizing agents, crosslinking agents and/orcustomary coatings additives and/or other dissolved solid, liquid orgaseous organic and/or inorganic substances of low and/or high molecularmass. In the context of the present invention, the term “minor amount”means an amount which does not change the aqueous nature of the aqueousmedium. The aqueous medium, however, may also comprise just water.

[0132] For the purpose of dispersion, the hydrophilic polyurethanes ofthe invention, containing the above-described (potentially) anionic orcationic hydrophilic groups, are neutralized with at least one of theabove-described neutralizing agents and subsequently are dispersed. Inthe case of the hydrophilic polyurethanes of the invention which containonly the nonionic hydrophilic functional groups, the use of neutralizingagents is unnecessary.

[0133] The resultant secondary polyurethane dispersions of the inventionare likewise outstandingly suited to the preparation of aqueous coatingmaterials, adhesives, and sealing compounds. In particular, they aresuitable for preparing the graft copolymers of the invention.

[0134] The graft copolymers of the invention are preparable by(co)polymerizing at least one monomer (a) in the presence of at leastone polyurethane of the invention.

[0135] If hydrophilic polyurethanes and predominantly hydrophobicmonomers (a) are employed in this preparation, it results in finelydivided graft copolymers of the invention having a hydrophobic corecomprising at least one copolymerized olefinically unsaturated monomer(a) and a hydrophilic shell comprising or consisting of at least onehydrophilic polyurethane of the invention. This variant of the graftcopolymers of the invention is prepared by dispersing at least onehydrophilic polyurethane of the invention in an aqueous medium, andsubsequently free-radically (co)polymerizing at least one hydrophobicolefinically unsaturated monomer (a) in its presence in emulsion.

[0136] If, on the other hand, hydrophobic polyurethanes andpredominantly hydrophilic monomers (a) are employed, the result isfinely divided graft copolymers of the invention having a hydrophobiccore comprising or consisting of at least one hydrophobic polyurethaneof the invention and a hydrophilic shell comprising at least onehydrophilic, olefinically unsaturated monomer (a) in copolymerized form.This variant is prepared by dispersing at least one hydrophobicpolyurethane of the invention in an aqueous medium. Advantageously, thisis done in a strong shear field. Viewed in terms of its method, thisprocess has no special features, but instead may take place, forexample, in accordance with the dispersion techniques described inEuropean Patent Application EP 0 401 565 A1. According to this, at leastone hydrophilic olefinically unsaturated monomer (a) is (co)polymerizedin the presence of the dispersed hydrophobic polyurethanes of theinvention.

[0137] All conceivable gradations of the hydrophilicity and,respectively, the hydrophobicity of the polyurethanes of the inventionon the one hand and of the monomers (a) on the other, between these twoextremes, are possible, so that it is also possible for graft copolymersof the invention to result which have no, or no pronounced, core-shellstructure.

[0138] Furthermore, the graft copolymers of the invention may beprepared using the (co)polymerization processes described below.

[0139] Examples of hydrophilic and hydrophobic monomers (a) suitable forpreparing the graft copolymers of the invention are the following:

[0140] Monomers (a1):

[0141] Hydroxyalkyl esters of acrylic acid, methacrylic acid or anotheralpha,beta-ethylenically unsaturated carboxylic acid which are derivedfrom an alkylene glycol which is esterified with the acid, or areobtainable by reacting the acid with alkylene oxide, especiallyhydroxyalkyl esters of acrylic acid, methacrylic acid or ethacrylic acidin which the hydroxyalkyl group contains up to 20 carbon atoms, such as2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 3-hydroxybutyl,4-hydroxybutyl acrylate, methacrylate, ethacrylate or crotonate;1,4-bis(hydroxymethyl)cyclohexane,octahydro-4,7-methano-1H-indenedimethanol or methylpropanediolmonoacrylate, monomethacrylate, monoethacrylate or monocrotonate; orreaction products of cyclic esters, such as ε-caprolactone, for example,and these hydroxyalkyl esters; or olefinically unsaturated alcohols suchas allyl alcohol or polyols such as trimethylolpropane monoallyl ordiallyl ether or pentaerythritol monoallyl, diallyl or triallyl ether.These monomers (a1) of higher functionality are generally used only inminor amounts. In the context of the present invention, minor amounts ofhigher-functional monomers here are amounts which do not result in thecrosslinking or gelling of the polyacrylate resins. Thus, for example,the proportion of trimethylolpropane monoallyl ether may be from 2 to10% by weight, based on the overall weight of the monomers (a1) to (a6)used to prepare the polyacrylate resin.

[0142] Monomers (a2):

[0143] (Meth)acrylic alkyl or cycloalkyl esters having up to 20 carbonatoms in the alkyl radical, especially methyl, ethyl, propyl, n-butyl,sec-butyl, tert-butyl, hexyl, ethylhexyl, stearyl and lauryl acrylate ormethacrylate; cycloaliphatic (meth)acrylic esters, especiallycyclohexyl, isobornyl, dicyclopentadienyl,octahydro-4,7-methano-1H-indenedimethanol or tert-butylcyclohexyl(meth)acrylate; (meth)acrylic oxaalkyl esters or oxacycloalkyl esterssuch as ethyltriglycol (meth)acrylate and methoxyoligoglycol(meth)acrylate having a molecular weight Mn of preferably 550; or otherethoxylated and/or propoxylated hydroxyl-free (meth)acrylic acidderivatives. These may include, in minor amounts, higher-functional(meth)acrylic alkyl or cycloalkyl esters such as ethylene glycol,propylene glycol, diethylene glycol, dipropylene glycol, butyleneglycol, 1,5-pentanediol, 1,6-hexanediol,octahydro-4,7methano-1H-indenedimethanol or cyclohexane-1,2-, -1,3- or-1,4-diol di(meth)acrylate; trimethylolpropane di- or tri(meth)acrylate;or pentaerythritol di-, tri- or tetra(meth)acrylate. In the context ofthe present invention, minor amounts of higher-functional monomers (a2)here are amounts which do not cause crosslinking or gelling of thepolyacrylate resins.

[0144] Monomers (a3):

[0145] Ethylenically unsaturated monomers which carry at least one acidgroup, preferably a carboxyl group, per molecule, or a mixture of suchmonomers. As monomers (a3) it is particularly preferred to use acrylicacid and/or methacrylic acid. It is also possible, however, to use otherethylenically unsaturated carboxylic acids having up to 6 carbon atomsin the molecule. Examples of such acids are ethacrylic acid, crotonicacid, maleic acid, fumaric acid, and itaconic acid. It is also possibleto use ethylenically unsaturated sulfonic or phosphonic acids, and/ortheir partial esters, as component (a3). Further suitable monomers (a3)include mono(meth)acryloyloxyethyl maleate, succinate, and phthalate.

[0146] Monomers (a4):

[0147] Vinyl esters of alpha-branched monocarboxylic acids having 5 to18 carbon atoms in the molecule. The branched monocarboxylic acids maybe obtained by reacting formic acid or carbon monoxide and water witholefins in the presence of a liquid, strongly acidic catalyst; theolefins may be cracking products from paraffinic hydrocarbons, such asmineral oil fractions, and may contain both branched and straight-chainacyclic and/or cycloaliphatic olefins. In the reaction of such olefinswith formic acid and/or with carbon monoxide and water, a mixture ofcarboxylic acids is formed in which the carboxyl groups are locatedpredominantly on a quaternary carbon atom. Other olefinic startingmaterials are, for example, propylene trimer, propylene tetramer, anddiisobutylene. Alternatively, the vinyl esters may be prepared in aconventional manner from the acids, for example, by reacting the acidwith acetylene. Particular preference—owing to their readyavailability—is given to the use of vinyl esters of saturated aliphaticmonocarboxylic acids having 9 to 11 carbon atoms and being branched onthe alpha carbon atom.

[0148] Monomers (a5):

[0149] Reaction product of acrylic acid and/or methacrylic acid with theglycidyl ester of an alpha-branched monocarboxylic acid having 5 to 18carbon atoms per molecule. The reaction of the acrylic or methacrylicacid with the glycidyl ester of a carboxylic acid having a tertiaryalpha carbon atom may take place before, during or after thepolymerization reaction. As component (a5) it is preferred to use thereaction product of acrylic and/or methacrylic acid with the glycidylester of Versatic® acid. This glycidyl ester is obtainable commerciallyunder the name Cardura® E10. For further details, reference is made toRömpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, NewYork, 1998, pages 605 and 606.

[0150] Monomers (a6):

[0151] Ethylenically unsaturated monomers essentially free from acidgroups, such as

[0152] olefins, such as ethylene, propylene, 1-butene, 1-pentene,1-hexene, cyclohexene, cyclopentene, norbornene, butadiene, isoprene,cyclopentadiene and/or dicyclopentadiene;

[0153] (meth)acrylamides such as (meth)acrylamide, N-methyl-,N,N-dimethyl-, N-ethyl-, N,N-diethyl-, N-propyl-, N,N-dipropyl,N-butyl-, N,N-dibutyl-, N-cyclohexyl- and/orN,N-cyclohexyl-methyl(meth)acrylamide;

[0154] monomers containing epoxide groups, such as the glycidyl ester ofacrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, maleicacid, fumaric acid and/or itaconic acid;

[0155] vinylaromatic hydrocarbons, such as styrene, alpha-alkylstyrenes,especially alpha-methylstyrene, and/or vinyltoluene;

[0156] diarylethylenes, especially those of the general formula III:

R¹²R¹³C=CR¹⁴R¹⁵  (III)

[0157] where the radicals R¹², R¹³, R¹⁴ and R¹⁵ each independently ofone another are hydrogen atoms or substituted or unsubstituted alkyl,cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl,cycloalkylaryl, arylalkyl or arylcycloalkyl radicals, with the provisothat at least two of the variables R¹², R¹³, R¹⁴ and R¹⁵ are substitutedor unsubstituted aryl, arylalkyl or arylcycloalkyl radicals, especiallysubstituted or unsubstituted aryl radicals. Examples of suitable alkylradicals are methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl,tert-butyl, amyl, hexyl or 2-ethylhexyl. Examples of suitable cycloalkylradicals are cyclobutyl, cyclopentyl or cyclohexyl. Examples of suitablealkylcycloalkyl radicals are methylenecyclohexane, ethylenecyclohexane,or 1,3-propanediylcyclohexane. Examples of suitable cyloalkylalkylradicals are 2-, 3- or 4-methyl- -ethyl-, -propyl- or-butylcyclohex-1-yl. Examples of suitable aryl radicals are phenyl,naphthyl or biphenylyl, preferably phenyl and naphthyl, and especiallyphenyl. Examples of suitable alkylaryl radicals are benzyl or ethylene-or 1,3propanediyl-benzene. Examples of suitable cycloalkylaryl radicalsare 2-, 3- or 4phenylcyclohex-1-yl. Examples of suitable arylalkylradicals are 2-, 3- or 4-methyl-, -ethyl-, -propyl- or -butylphen-l-yl.Examples of suitable arylcycloalkyl radicals are 2-, 3- or4-cyclohexylphen-1-yl. The aryl radicals R¹², R¹³, R¹⁴ and/or R¹⁵ arepreferably phenyl or naphthyl radicals, especially phenyl radicals. Thesubstituents that may be present in the radicals R¹², R¹³, R¹⁴ and/orR¹⁵ are electron withdrawing or electron donating atoms or organicradicals, especially halogen atoms, nitrile, nitro, partially or fullyhalogenated alkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl,alkylaryl, cycloalkylaryl, arylalkyl and arylcycloalkyl radicals;aryloxy, alkyloxy and cycloalkyloxy radicals; arylthio, alkylthio andcycloalkylthio radicals, and/or primary, secondary and/or tertiary aminogroups. Diphenylethylene, dinaphthaleneethylene, cis- or trans-stilbene,vinylidene-bis(4-N,N-dimethylaminobenzene),vinylidenebis(4-aminobenzene) or vinylidenebis(4-nitrobenzene),especially diphenylethylene (DPE), are particularly advantageous and soare used with preference. Preferably, these monomers (a6) are used notas the sole monomers but rather always together with other monomers (a),in which case they regulate the copolymerization advantageously suchthat free-radical copolymerization in batch mode is also possible;

[0158] nitrites such as acrylonitrile and/or methacrylonitrile;

[0159] vinyl compounds such as vinyl chloride, vinyl fluoride,vinylidene dichloride, vinylidene difluoride; N-vinylpyrrolidone; vinylethers such as ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinylether, n-butyl vinyl ether, isobutyl vinyl ether and/or vinyl cyclohexylether; vinyl esters such as vinyl acetate, vinyl propionate, vinylbutyrate, vinyl pivalate, vinyl esters of Versatic® acids, which aremarketed under the brand name VeoVa® by the company Deutsche ShellChemie (for further details, reference is made to Römpp Lexikon Lackeund Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, page598 and also pages 605 and 606), and/or the vinyl ester of2-methyl-2-ethylheptanoic acid; and/or

[0160] polysiloxane macromonomers having a number-average molecularweight Mn of from 1000 to 40,000, preferably from 2000 to 20,000, withparticular preference from 2500 to 10,000, and in particular from 3000to 7000, and having on average from 0.5 to 2.5, preferably from 0.5 to1.5, ethylenically unsaturated double bonds per molecule, as aredescribed in DE 38 07 571 A1 on pages 5 to 7, in DE 37 06 095 A1 incolumns 3 to 7, in EP 0 358 153 B1 on pages 3 to 6, in U.S. Pat. No.4,754,014 A in columns 5 to 9, in DE 44 21 823 A1, or in internationalPatent Application WO 92/22615 on page 12 line 18 to page 18 line 10, oracryloxysilane-containing vinyl monomers, preparable by reactinghydroxy-functional silanes with epichlorohydrin and then reacting thereaction product with methacrylic acid and/or hydroxyalkyl esters of(meth)acrylic acid.

[0161] From these suitable monomers (a) described above by way ofexample, the skilled worker is easily able to select, on the basis oftheir known physicochemical properties and reactivities, the hydrophilicor hydrophobic monomers (a) that are particularly suitable for theintended use in question. If desired, he or she may for this purposeconduct a few preliminary rangefinding experiments. In particular, he orshe will be careful to ensure that monomers (a) contain no functionalgroups, especially (potentially) ionic functional groups, which enterinto unwanted interactions with the (potentially) ionic functionalgroups in the hydrophilic polyurethanes of the invention.

[0162] In accordance with the invention, particular advantages result ifthe monomers (a) are selected such that the profile of properties of thegrafted (co)polymers is determined essentially by the above-describedhydrophilic or hydrophobic (meth)acrylate monomers (a), the othermonomers (a) advantageously providing broad variation of this profile ofproperties.

[0163] In accordance with the invention, very particular advantagesresult from using mixtures of the monomers (a1), (a2) and (a6) and also,if desired, (a3).

[0164] Viewed in terms of method, the preparation of the graftcopolymers of the invention has no special features but instead takesplace in accordance with the customary and known methods of free-radical(co)polymerization in bulk, solution or emulsion in the presence of atleast one polymerization initiator.

[0165] Where the (co)polymerization takes place in bulk or solution, thegraft copolymer of the invention may be used or processed further inthis form. In particular, it is dispersed in an aqueous medium, sogiving a secondary dispersion of the invention.

[0166] The (co)polymerization is preferably conducted in emulsion, suchas is described, for example, in patent DE 197 22 862 C1 or in patentapplications DE 196 45 761 A1, EP-A-522 419 A1 or EP 0 522 420 A1, or inminiemulsion or microemulsion. Regarding miniemulsion and microemulsion,reference is made, for further details, to the patent applications andthe literature references DE 196 28 142 A1, DE 196 28 143 A1 or EP 0 401565 A1, emulsion polymerization and emulsion polymers, editors P. A.Lovell and Mohamed S. El-Aasser, John Wiley and Sons, Chichester, NewYork, Weinheim, 1997, pages 700 et seq.; Mohamed S. El-Aasser, Advancesin Emulsion Polymerization and Latex Technology, 30th Annual ShortCourse, Volume 3, Jun. 7-11, 1999, Emulsion Polymers Institute, LehighUniversity, Bethlehem, Pa., U.S.A. In the case of (co)polymerization inemulsion, miniemulsion or microemulsion, the graft copolymers of theinvention are obtained in the form of primary dispersions of theinvention.

[0167] Suitable reactors for the (co)polymerization processes are thecustomary and known stirred vessels, cascades of stirred vessels, tubereactors, loop reactors or Taylor reactors, as described, for example,in patents DE-B-1 071 241 A1, EP 0 498 583 A1 or DE 198 28 742 A1 or inthe article by K. Kataoka in Chemical Engineering Science, Volume 50,No. 9, 1995, pages 1409 to 1416.

[0168] The (co)polymerization is advantageously conducted attemperatures above room temperature and below the lowest decompositiontemperature of the monomers used in each case, the temperature rangechosen being preferably from 30 to 180° C., with very particularpreference from 70 to 150° C., and in particular from 80 to 110° C.

[0169] Where especially volatile monomers (a) and/or emulsions are used,the (co)polymerization may also be conducted under superatmosphericpressure, preferably under from 1.5 to 3000 bar, with particularpreference from 5 to 1500 bar, and in particular from 10 to 1000 bar.

[0170] Examples of suitable polymerization initiators are initiatorswhich form free radicals, such as dialkyl peroxides, such asdi-tert-butyl peroxide or dicumyl peroxide; hydroperoxides, such ascumene hydroperoxide or tert-butyl hydroperoxide; peresters, such astert-butyl perbenzoate, tert-butyl perpivalate, tert-butylper-3,5,5-trimethylhexanoate, or tert-butyl per-2-ethylhexanoate;potassium, sodium or ammonium peroxodisulfate; azo dinitriles such asazobisisobutyronitrile; C—C-cleaving initiators such as benzpinacolsilyl ether; or a combination of a nonoxidizing initiator with hydrogenperoxide. Preference is given to the use of water-insoluble initiators.The initiators are used preferably in an amount of from 0.1 to 25% byweight, with particular preference from 2 to 10% by weight, based on theoverall weight of the monomers (a).

[0171] In the graft copolymers of the invention the proportion of coreto shell or of polyurethane of the invention to grafted-on monomers (a)may vary extremely widely, which is a particular advantage of the graftcopolymers of the invention. This ratio is preferably from 1:100 to100:1, more preferably from 1:50 to 50:1, with particular preferencefrom 30:1 to 1:30, with very particular preference from 20:1 to 1:20,and in particular from 10:1 to 1:10. Very particular advantages resultif this ratio is approximately from 3.5:1 to 1:3.5, in particular from1.5:1 to 1:1.5.

[0172] The graft copolymers of the invention may be isolated from theprimary dispersions in which they are produced and may be passed on fora very wide variety of end uses, especially in solventborne, water- andsolvent-free pulverulent solid or water- and solvent-free liquid coatingmaterials, adhesives, and sealing compounds. In accordance with theinvention, however, it is of advantage to use the primary dispersions assuch se to prepare aqueous coating materials, adhesives, and sealingcompounds.

[0173] In addition to the polyurethanes of the invention and the graftcopolymers of the invention, the aqueous adhesives of the invention maycomprise further suitable customary and known constituents in effectiveamounts. Examples of suitable constituents are the crosslinking agentsand additives described below, provided they are suitable for preparingadhesives.

[0174] In addition to the polyurethanes of the invention and the graftcopolymers of the invention, the aqueous sealing compounds of theinvention may likewise comprise further suitable customary and knownconstituents in effective amounts. Examples of suitable constituents arelikewise the crosslinking agents and additives described below, providedthey are suitable for preparing sealing compounds.

[0175] The primary dispersions of the graft copolymers of the inventionare especially suitable for preparing the aqueous coating materials ofthe invention, especially the aqueous coating materials of theinvention. Examples of aqueous coating materials of the invention aresurfacers, solid-color topcoats, aqueous basecoats, and clearcoats. Theprimary dispersions of the invention develop very particular advantageswhen used to prepare the aqueous basecoats of the invention.

[0176] In the aqueous basecoats of the invention, the polyurethanesand/or the graft copolymers of the invention, but especially the graftcopolymers of the invention, are present advantageously in an amount offrom 1.0 to 50, preferably from 2.0 to 40, with particular preferencefrom 3.0 to 35, with very particular preference from 4.0 to 30, and inparticular from 5.0 to 25% by weight, based in each case on the overallweight of the respective aqueous basecoat of the invention.

[0177] The further essential constituent of the aqueous basecoat of theinvention is at least one color and/or effect pigment. The pigments maycomprise organic or inorganic compounds. On the basis of this largenumber of appropriate pigments, therefore, the aqueous basecoat of theinvention ensures a universal scope for use and makes it possible torealize a large number of color shades and optical effects.

[0178] Effect pigments which may be used include metal flake pigmentssuch as commercial aluminum bronzes, aluminum bronzes chromated inaccordance with DE-A-36 36 183, commercial stainless steel bronzes, andnonmetallic effect pigments, such as pearlescent pigments andinterference pigments, for example. For further details, reference ismade to Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, 1998,page 176, “Effect pigments” and pages 380 and 381 “Metal oxide-micapigments” to “Metal pigments”.

[0179] Examples of suitable inorganic color pigments are titaniumdioxide, iron oxides, sicotrans yellow, and carbon black. Examples ofsuitable organic color pigments are thioindigo pigments, indanthreneblue, Cromophthal red, Irgazine orange and Heliogen green. For furtherdetails, reference is made to Römpp Lexikon Lacke und Druckfarben, GeorgThieme Verlag, 1998, pages 180 and 181, “Iron blue pigments” to “Blackiron oxide”, pages 451 to 453 “Pigments” to “Pigment volumeconcentration”, page 563 “Thioindigo pigments”, and page 567 “Titaniumdioxide pigments”.

[0180] The proportion of the pigments in the aqueous basecoat of theinvention may vary extremely widely and is guided in particular by thehiding power of the pigments, by the desired shade, and by the desiredoptical effect. Preferably, the pigments are present in the aqueousbasecoat of the invention in an amount of from 0.5 to 50, morepreferably from 0.5 to 45, with particular preference from 0.5 to 40,with very particular preference from 0.5 to 35, and in particular from0.5 to 30% by weight, based in each case on the overall weight of theaqueous basecoat of the invention. In this context, the pigment/binderratio, i.e., the ratio of the pigments to the polyurethanes of theinvention and/or to the graft copolymers of the invention, and alsoother binders that may be present, may vary extremely widely.Preferably, this ratio is from 6.0:1.0 to 1.0:50, more preferably from5:1.0 to 1.0:50, with particular preference from 4.5:1.0 to 1.0:40, withvery particular preference from 4:1.0 to 1.0:30, and in particular from3.5:1.0 to 1.0:25.

[0181] These pigments may also be incorporated into the aqueousbasecoats of the invention by way of pigment pastes, in which casesuitable grinding resins include, inter alia, the polyurethanes of theinvention and/or the graft copolymers of the invention.

[0182] These pigments are omitted when the coating material of theinvention is used as a clearcoat.

[0183] The coating material of the invention, especially the aqueousbasecoat of the invention, may comprise at least one crosslinking agent.

[0184] Examples of suitable crosslinking agents are amino resins, asdescribed for example in Römpp Lexikon Lacke und Druckfarben, GeorgThieme Verlag, 1998, page 29, “Amino resins”, in the text book“Lackadditive” [Coatings additives] by Johan Bieleman, Wiley-VCH,Weinheim, New York, 1998, pages 242 et seq., in the book “Paints,Coatings and Solvents”, second, completely revised edition, edited by D.Stoye and W. Freitag, Wiley-VCH, Weinheim, New York, 1998, pages 80 ff.,in patents U.S. Pat. No. 4 710 542 A1 or EP-B-0 245 700 A1, and in thearticle by B. Singh and coworkers, “Carbamylmethylated melamines, NovelCrosslinkers for the Coatings Industry” in Advanced Organic CoatingsScience and Techology Series, 1991, Volume 13, pages 193 to 207;carboxyl-containing compounds or resins, as described for example inpatent DE 196 52 813 A1; compounds or resins containing epoxide groups,as described for example in patents EP 0 299 420 A1, DE 22 14 650 B1, DE27 49 576 B1, U.S. Pat. No. 4,091,048 A1 or U.S. Pat. No. 3,781,379 A1;blocked and nonblocked polyisocyanates, as described for example inpatents U.S. Pat. No. 4,444,954 A1, DE 196 17 086 A1, DE 196 31 269 A1,EP 0 004 571 A1 or EP 0 582 051 A1; and/ortris(alkoxycarbonylamino)triazines, as described in patents U.S. Pat.No. 4,939,213 A1, U.S. Pat. No. 5,084,541 A1, U.S. Pat. No. 5,288,865 A1or EP 0 604 922 A1.

[0185] The epoxides and the nonblocked polyisocyanates, especially thepolyisocyanates, are employed in two-component or multicomponentsystems.

[0186] Where the aqueous basecoats of the invention are one-componentsystems, it is preferred to use amino resins as the predominant or solecrosslinking agents. The other abovementioned crosslinking agents may beused as additional crosslinking agents for further advantageousvariation of the profile of properties of the aqueous basecoats of theinvention and of the basecoats of the invention and multicoat colorand/or effect coating systems of the invention produced therefrom, inwhich case their proportion among the crosslinking agents is <50% byweight.

[0187] Preferably, the crosslinking agents are employed in the aqueousbasecoats of the invention in an amount of from 0.1 to 30, morepreferably from 0.3 to 20, with particular preference from 0.5 to 10,and in particular from 1.0 to 8.0% by weight, based in each case on theoverall weight of the respective aqueous basecoat of the invention.

[0188] In addition to the above-described constituents, the coatingmaterial of the invention, especially the aqueous basecoat, may comprisecustomary and known binders and/or additives in effective amounts.

[0189] Examples of customary and known binders are oligomeric andpolymeric, thermally curable, linear and/or branched and/or block, comband/or random poly(meth)acrylates or acrylate copolymers, especiallythose described in patent DE 197 36 535 A1, polyesters, especially thosedescribed in patents DE 40 09 858 A1 or DE 44 37 535 A1, alkyds,acrylated polyesters, polylactones, polycarbonates, polyethers, epoxyresinamine adducts, (meth)acrylate diols, partially hydrolyzed polyvinylesters, polyurethanes and acrylated polyurethanes, as described inpatents EP 0 521 928 A1, EP 0 522 420 A1, EP 0 522 419 A1, EP 0 730 613A1 or DE 44 37 535 A1, or polyureas.

[0190] If the coating material of the invention is to be curable notonly thermally but also with actinic radiation, especially UV radiationand/or electron beams (dual cure), it comprises at least one constituentwhich is activatable with actinic radiation.

[0191] Suitable activatable constituents are in principle all oligomericand polymeric compounds that are curable with actinic radiation,especially UV radiation and/or electron beams, and which are commonlyused in the field of UV-curable or electron-beam-curable coatingmaterials.

[0192] It is advantageous to use radiation-curable binders asactivatable constituents. Examples of suitable radiation-curable bindersare (meth)acrylic-functional (meth)acrylic copolymers, polyetheracrylates, polyester acrylates, unsaturated polyesters, epoxy acrylates,urethane acrylates, amino acrylates, melamine acrylates, siliconeacrylates, isocyanato acrylates, and the corresponding methacrylates. Itis preferred to use binders which are free from aromatic structuralunits. Preference is therefore given to the use of urethane(meth)acrylates and/or polyester (meth)acrylates, aliphatic urethaneacrylates being particularly preferred.

[0193] Examples of suitable additives are

[0194] organic and inorganic fillers such as chalk, calcium sulfate,barium sulfate, silicates such as talc or kaolin, silicas, oxides suchas aluminum hydroxide or magnesium hydroxide, or organic fillers such astextile fibers, cellulose fibers, polyethylene fibers or wood flour; forfurther details reference is made to Römpp Lexikon Lacke undDruckfarben, Georg Thieme Verlag, 1998, pages 250 ff., “Fillers”;

[0195] thermally curable reactive diluents such as positionally isomericdiethyloctanediols or hydroxyl-containing hyperbranched compounds ordendrimers, as described in patent applications DE 198 09 643 A1, DE 19840 605 A1 or DE 198 05 421 A1;

[0196] reactive diluents curable with actinic radiation, as described inRömpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, NewYork, 1998, on page 491 under the entry “Reactive diluents”;

[0197] photoinitiators and coinitiators, as described in Römpp LexikonLacke und Druckfarben, Georg Thieme Verlag, Stuttgart, 1998, pages 444to 446;

[0198] low-boiling and/or high-boiling organic solvents (“longsolvents”);

[0199] UV absorbers;

[0200] light stabilizers such as HALS compounds, benzotriazoles oroxalanilides;

[0201] free-radical scavengers;

[0202] thermally labile free-radical initiators such as organicperoxides, organic azo compounds or C—C-cleaving initiators such asdialkyl peroxides, peroxocarboxylic acids, peroxodicarbonates, peroxideesters, hydroperoxides, ketone peroxides, azo dinitriles or benzpinacolsilyl ether;

[0203] crosslinking catalysts such as dibutyltin dilaurate, lithiumdecanoate or zinc octoate, or amine-blocked organic sulfonic acids;

[0204] devolatilizers such as diazadicycloundecane;

[0205] slip additives;

[0206] polymerization inhibitors;

[0207] defoamers;

[0208] emulsifiers, especially nonionic emulsifiers such as alkoxylatedalkanols, polyols, phenols and alkylphenols or anionic emulsifiers suchas alkali metal salts or ammonium salts of alkanecarboxylic acids,alkanesulfonic acids and sulfo acids of alkoxylated alkanols, polyols,phenols and alkylphenols;

[0209] wetting agents such as siloxanes, fluorine compounds, carboxylicmonoesters, phosphates, polyacrylic acids and their copolymers, orpolyurethanes;

[0210] adhesion promoters such as tricyclodecanedimethanol;

[0211] leveling agents;

[0212] film-forming auxiliaries such as cellulose derivatives;

[0213] transparent fillers based on titanium dioxide, silica, alumina orzirconium oxide; for further details reference is made to Römpp LexikonLacke und Druckfarben, Georg Thieme Verlag, Stuttgart, 1998, pages 250to 252;

[0214] rheology control additives, such as those known from patents WO94/22968, EP 0 276 501 A1, EP 0 249 201 A1 or WO 97/12945; crosslinkedpolymeric microparticles, as disclosed for example in EP 0 008 127 A1;inorganic phyllosilicates, preferably smectites, especiallymontmorillonites and hectorites, such as aluminum-magnesium silicates,sodium-magnesium and sodium-magnesium-fluorine-lithium phyllosilicatesof the montmorillonite type or inorganic phyllosilicates such asaluminum-magnesium silicates, sodium-magnesium andsodium-magnesium-fluorine-lithium phyllosilicates of the montmorillonitetype (for further details reference is made to the book by JohanBieleman, “Lackadditive”, Wiley-VCH, Weinheim, New York, 1998, pages 17to 30); silicas such as Aerosils; or synthetic polymers containing ionicand/or associative groups such as polyvinyl alcohol,poly(meth)acrylamide, poly(meth)acrylic acid, polyvinylpyrrolidone,styrene-maleic anhydride or ethylene-maleic anhydride copolymers andtheir derivatives or hydrophobically modified polyacrylates; orassociative thickeners based on polyurethane, as described in RömppLexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, New York,1998, “Thickeners”, pages 599 to 600, and in the textbook “Lackadditive”by Johan Bieleman, Wiley-VCH, Weinheim, New York, 1998, panes 51 to 59and 65; and/or

[0215] flame retardants.

[0216] Further examples of suitable coatings additives are described inthe textbook “Lackadditive” by Johan Bieleman, Wiley-VCH, Weinheim, NewYork, 1998.

[0217] The aqueous basecoats of the invention preferably have sprayviscosity and a solids content of from 5.0 to 60, more preferably from10 to 60, with particular preference from 13 to 60, and in particularfrom 13 to 55% by weight, based in each case on the overall weight ofthe respective aqueous basecoat of the invention.

[0218] The preparation of the aqueous basecoat of the invention has nospecial features but instead takes place in a customary and known mannerby mixing of the above-described constituents in appropriate mixingequipment such as stirred vessels, dissolvers, stirred mills orextruders in accordance with the techniques suitable for preparing therespective aqueous basecoats.

[0219] The aqueous basecoat of the invention is used to produce thecoatings of the invention, especially multicoat coating systems, onprimed or unprimed substrates.

[0220] Suitable substrates are all surfaces for coating which are notdamaged by curing of the coatings present thereon using heat, or heatand actinic radiation. Suitable substrates comprise, for example,metals, plastics wood, ceramic, stone, textile, fiber assemblies,leather, glass, glass fibers, glass wool and rock wool, mineral-boundand resin-bound building materials, such as plasterboards and cementboards or roof tiles, and composites of these materials. Accordingly,the aqueous basecoat of the invention is suitable for applicationsoutside that of vehicle finishing as well. In this context it isparticularly suitable for the coating of furniture and for industrialcoating, including coil coating, container coating, and the impregnationor coating of electrical components. In the context of industrialcoatings it is suitable for coating virtually all parts for domestic orindustrial use, such as radiators, domestic appliances, small metalparts such as screws and nuts, wheel caps, wheel rims, packaging, orelectrical components such as motor windings or transformer windings.

[0221] The comments made above also apply, mutatis mutandis, to thesurfacers, solid-color topcoats, and clearcoats of the invention, and tothe adhesives and sealing compounds of the invention.

[0222] In the case of electrically conductive substrates it is possibleto use primers, which are prepared in a customary and known manner fromelectrodeposition coating materials. Both anodic and cathodicelectrodeposition coating materials are suitable for this purpose, butespecially cathodics.

[0223] With the multicoat coating system of the invention it is alsopossible to coat primed or unprimed plastics such as, for example, ABS,AMMA, ASA, CA, CAB, EP, UF, CF, MF, MPF, PF, PAN, PA, PE, HDPE, LDPE,LLDPE, UHMWPE, PET, PMMA, PP, PS, SB, PUR, PVC, RF, SAN, PBT, PPE, POM,PUR-RIM, SMC, BMC, PP-EPDM and UP (abbreviations to DIN 7728P1) and alsopolymer blends thereof or the fiber-reinforced composite materialsproduced using these plastics.

[0224] In the case of unfunctionalized and/or apolar substrate surfaces,these may be subjected prior to coating in a known manner to apretreatment, such as with a plasma or by flaming, or may be providedwith an aqueous primer.

[0225] The multicoat coating systems of the invention may be produced ina variety of ways in accordance with the invention.

[0226] A first preferred variant of the process of the inventioncomprises the following process steps:

[0227] (I) preparing a basecoat film by applying the aqueous basecoat ofthe invention to the substrate,

[0228] (II) drying the basecoat film,

[0229] (III) preparing a clearcoat film by applying a clearcoat materialto the basecoat film, and

[0230] (IV) jointly curing the basecoat film and the clearcoat film, togive the basecoat and the clearcoat (wet-on-wet technique).

[0231] This variant offers particular advantages especially in thecontext of the coating of plastics, and is therefore employed withparticular preference in that utility.

[0232] A second preferred variant of the process of the inventioncomprises the following steps:

[0233] (I) preparing a surfacer film by applying a surfacer to thesubstrate,

[0234] (II) curing the surfacer film, to give the surfacer coat,

[0235] (III) preparing a basecoat film by applying the aqueous basecoatof the invention to the surfacer coat,

[0236] (IV) drying the basecoat film,

[0237] (V) preparing a clearcoat film by applying a clearcoat materialto the basecoat film, and

[0238] (VI) jointly curing the basecoat film and the clearcoat film, togive the basecoat and the clearcoat (wet-on-wet technique).

[0239] A third preferred variant of the process of the inventioncomprises the following steps:

[0240] (I) preparing a surfacer film by applying a surfacer to thesubstrate,

[0241] (II) drying the surfacer film,

[0242] (III) preparing a basecoat film by applying the aqueous basecoatof the invention to the surfacer film,

[0243] (IV) drying the basecoat film,

[0244] (V) preparing a clearcoat film by applying a clearcoat materialto the basecoat film, and

[0245] (VI) jointly curing the surfacer film, the basecoat film and theclearcoat film, to give the surfacer, the basecoat and the clearcoat(extended wet-on-wet technique).

[0246] A fourth preferred variant of the process of the inventioncomprises the following steps:

[0247] (I) depositing an electrodeposition coating film on thesubstrate,

[0248] (II) drying the electrodeposition coating film,

[0249] (II) preparing a first basecoat film by applying a first basecoatmaterial to the electrodeposition coating film,

[0250] (III) jointly curing the electrodeposition coating film and thefirst basecoat film, to give the electrodeposition coating and the firstbasecoat (wet-on-wet technique),

[0251] (IV) preparing a second basecoat film by applying a secondbasecoat material to the first basecoat,

[0252] (V) drying the second basecoat film,

[0253] (VI) preparing a clearcoat film by applying a clearcoat materialto the basecoat film, and

[0254] (VII) jointly curing the second basecoat film and clearcoat film,to give the second basecoat and the clearcoat (wet-on-wet technique).

[0255] The three last-mentioned variants offer particular advantagesespecially in the context of the coating of automobile bodies and aretherefore employed with very particular preference in that utility.

[0256] It is a further particular advantage of the aqueous basecoat ofthe invention and of the processes of the invention that the aqueousbasecoat may be combined not only with the surfacer of the invention butalso with all customary and known surfacers.

[0257] Yet another special advantage of the aqueous basecoat of theinvention and of the process of the invention proves to be that theaqueuos basecoat may be combined not only, outstandingly, with theclearcoat material of the invention but also with all customary andknown clearcoat materials.

[0258] Clearcoat materials which are known per se are one-component ormulticomponent clearcoats, powder clearcoats, powder slurry clearcoats,UV-curable clearcoats, or sealers, as known from the patentapplications, patents and publications DE 42 04 518 A1, EP 0 594 068 A1,EP 0 594 071 A1, EP 0 594 142 A1, EP 0 604 992 A1, EP 0 596 460 A1, WO94/10211, WO 94/10212, WO 94/10213, WO 94/22969 or WO 92/22615, U.S.Pat. No. 5,474,811 A1, U.S. Pat. No. 5,356,669 A1 or U.S. Pat. No.5,605,965 A1, DE 42 22 194 A1, in the product information from BASFLacke+Farben AG entitled “Pulverlacke” [Powder coatings], 1990, in theBASF Coatings AG company brochure “Pulverlacke, Pulverlacke furindustrielle Anwendungen” [Powder coating materials, powder coatings forindustrial applications], January 2000, U.S. Pat. No. DE 195 40 977 A1,DE 195 18 392 A1, 4,268,542 A1, DE 196 17 086 A1, DE-A-196 13 547, DE196 52 813 A1, DE-A-198 14 471 A1, EP 0 928 800 A1, EP 0 636 669 A1, EP0 410 242 A1, EP 0 783 534 A1, EP 0 650 978 A1, EP 0 650 979 A1, EP 0650 985 A1, EP 0 540 884 A1, EP 0 568 967 A1, EP 0 054 505 A1, EP 0 002866 A1, DE 197 09 467 A1, DE 42 03 278 A1, DE 33 16 593 A1, DE 38 36 370A1, DE 24 36 186 A1, DE 20 03 579 B1, WO 97/46549, WO 99/14254, U.S.Pat. No. 5,824,373 A1, U.S. Pat. No. U.S. Pat. No. U.S. Pat. No.4,675,234 A1, 4,634,602 A1, 4,424,252 A1, U.S. Pat. No. U.S. Pat. No.U.S. Pat. No. 4,208,313 A1, 4,163,810 A1, 4,129,488 A1, U.S. Pat. No.U.S. Pat. No. EP 0 844 286 A1, 4,064,161 A1, 3,974,303 A1, DE 43 03 570A1, DE 34 07 087 A1, DE 40 11 045 A1, DE 40 25 215 A1, DE 38 28 098 A1,DE 40 20 316 A1 or DE 41 22 743 A1.

[0259] Powder slurry clearcoats offer particular advantages for themulticoat color and/or effect coating system of the invention and aretherefore used with particular preference in accordance with theinvention.

[0260] Furthermore, the clearcoats may additionally be coated furtherwith at least one other clearcoat, for example, an organically modifiedceramic layer, thereby making it possible to improve significantly thescratch resistance of the multicoat coating system of the invention.

[0261] The aqueous basecoat of the invention may be applied by allcustomary application methods, such as spraying, knifecoating, brushing,flowcoating, dipping, impregnating, trickling, or rolling, for example.The substrate to be coated may itself be at rest, with the applicationequipment or unit being moved. Alternatively, the substrate to becoated, especially a coil, may be moved, with the application unit beingat rest relative to the substrate or being moved appropriately.

[0262] Preference is given to the use of spray application methods, suchas compressed-air spraying, airless spraying, high-speed rotation,electrostatic spray application (ESTA), alone or in conjunction with hotspray applications such as hot-air spraying, for example. Applicationmay be conducted at temperatures of max. 70 to 80° C., so that suitableapplication viscosities are achieved without the short-term thermalstress being accompanied by any change in or damage to the aqueousbasecoat or its overspray, which may be intended for reprocessing. Forinstance, hot spraying may be configured such that the aqueous basecoatis heated in the spray nozzle for only a very short time, or is heatedjust a short way upstream of the spray nozzle.

[0263] The spray booth used for the application may be operated, forexample, with an optionally temperature-controllable circulation, whichis operated with an appropriate absorption medium for the overspray, anexample being the aqueous basecoat itself.

[0264] In general, the surfacer coating film, basecoat film andclearcoat film are applied in a wet film thickness such that they cureto give coats having the coat thicknesses which are necessary andadvantageous for their functions. In the case of the surfacer coat, thiscoat thickness is from 10 to 150, preferably from 10 to 120, withparticular preference from 10 to 100, and in particular from 10 to 90μm; in the case of the basecoat it is from 5 to 50, preferably from 5 to40, with particular preference from 5 to 30, and in particular from 10to 25 μm; and in the case of the clearcoats it is from 10 to 100,preferably from 15 to 80, with particular preference from 20 to 70, andin particular from 25 to 60 μm. It is also possible, however, to employthe multicoat system known from European Patent Application EP 0 817 614A1, comprising an electrodeposition coat, a first basecoat, a secondbasecoat, and a clearcoat, in which the overall coat thickness of thefirst and second basecoats is from 15 to 40 μm and the coat thickness ofthe first basecoat is from 20 to 50% of said overall coat thickness.

[0265] The surfacer coating film, basecoat film and clearcoat film arecleared thermally, or thermally and with actinic radiation (dual cure).

[0266] Full curing may take place after a certain rest time. Itsduration may be from 30 s to 2 h, preferably from 1 min to 1 h, and inparticular from 1 min to 45 min. The rest time serves, for example, forthe coating films to flow and undergo devolatilization, or for theevaporation of volatile constituents such as solvents. The rest time maybe assisted and/or shortened by the application at elevated temperaturesof up to 90° C. and/or by a reduced atmospheric humidity <10 g water/kgair, especially <5 g/kg air, provided this does not entail any damage orchange to the coating films, such as premature complete crosslinking,for instance.

[0267] The thermal curing has no special features in terms of its methodbut instead takes place in accordance with the customary and knownmethods, such as heating in a convection oven or irradiation with IRlamps. This thermal curing may also take place in stages.

[0268] Advantageously, thermal curing takes place at a temperature offrom 50 to 100° C., with particular preference from 60 to 100° C., andin particular from 80 to 100° C., for a time of from 1 min up to 2 h,with particular preference from 2 min up to 1 h, and in particular from3 min to 45 min. This process is employed in particular in the case oftwo-component or multicomponent systems.

[0269] If one-component systems and substrates of high heat-resistanceare used, thermal crosslinking may also be conducted at temperaturesabove 1000C. In this case it is generally advisable not to exceedtemperatures of 180° C., preferably 160° C., and in particular 155° C.

[0270] Curing with actinic radiation is preferably conducted with UVradiation and/or electron beams. It is preferred to employ a dose offrom 1000 to 3000, preferably from 1100 to 2900, with particularpreference from 1200 to 2800, with very particular preference from 1300to 2700, and in particular from 1400 to 2600 mJ/cm². If desired, thiscuring may be supplemented by actinic radiation from other radiationsources. In the case of electron beams, it is preferred to operate underan inert gas atmosphere. This may be ensured, for example, by supplyingcarbon dioxide and/or nitrogen directly to the surface of the coatingfilms. When curing with UV radiation, as well, it is also possible tooperate under inert gas in order to prevent the formation of ozone.

[0271] For curing with actinic radiation, the customary and knownradiation sources and optical auxiliary measures are employed. Examplesof suitable radiation sources are flashlights from the company VISIT,high-pressure or low-pressure mercury vapor lamps, with or without leaddoping in order to open up a radiation window of up to 405 nm, orelectron beam sources. The arrangement of these sources is known inprinciple and may be adapted to the circumstances of the workpiece andthe process parameters. In the case of workpieces of complex shape, asenvisaged for automobile bodies, the regions not accessible to directradiation (shadow regions) such as cavities, folds and other structuralundercuts may be (partially) cured using point emitters, small surfacearea emitters or circular emitters, in combination with an automaticmovement means for the irradiation of cavities or edges.

[0272] The apparatus and conditions for these curing methods aredescribed, for example, in R. Holmes, U.V. and E.B. Curing Formulationsfor Printing Inks, Coatings and Paints, SITA Technology, Academic Press,London, United Kingdom 1984.

[0273] Curing may be carried out in stages, i.e., by means of multipleexposure to light or with actinic radiation. It may also be carried outalternatingly; ie., curing is conducted in alternation with UV radiationand electron beams.

[0274] If thermal curing and curing with actinic radiation are employedtogether, these methods may be used simultaneously or in alternation. Ifthe two curing methods are used in alternation, it is possible, forexample, to begin with thermal curing and to end with actinic radiationcuring. In other cases it may prove advantageous to begin with curingwith actinic radiation and to end with it. Particular advantages resultif the aqueous basecoat film is cured in two separate process steps,first with actinic radiation and then thermally.

[0275] The application and curing techniques described above are alsoemployed with the other coating films (surfacer films, solid-colortopcoat films, clearcoat films) and also with the adhesives and sealingcompounds of the invention.

[0276] The multicoat coating systems of the invention exhibit anoutstanding profile of properties which is very well balanced in termsof mechanics, optics, corrosion resistance, and adhesion. Thus themulticoat coating systems of the invention possess the high opticalquality and intercoat adhesion required by the market and do not giverise to any problems such as deficient condensation resistance, cracking(mudcracking) or leveling defects, or surface structures in theclearcoats.

[0277] In particular, the multicoat coating systems of the inventionexhibit an outstanding metallic effect, an excellent D.O.I.(distinctness of the reflected image), and an outstanding surfacesmoothness. They are weathering-stable, resistant to chemicals and birddroppings, are scratch resistant, and exhibit very good reflow behavior.

[0278] Last but not least, however, it proves to be a very specialadvantage that through the use of the aqueous basecoats of the inventionin the production of the multicoat coatings of the invention no crackingor popping marks result even when the aqueous basecoat films areovercoated with powder slurry clearcoats and subsequently baked togetherwith them. By this means it is possible to combine the particularadvantages of aqueous basecoats with the particular advantages of powderslurry clearcoats. Moreover, these very multicoat coating systems of theinvention prove to be particularly firmly adhering, even when used asrefinishes.

[0279] The adhesives and sealing compounds of the invention areoutstandingly suitable for the production of adhesive films and seals,which retain particularly high bond strength and particularly highsealing capacity even under extreme and/or rapidly changing climaticconditions.

[0280] Accordingly, the primed or unprimed substrates of the inventioncoated with at least one coating of the invention, bonded with at leastone adhesive film of the invention, and/or sealed with at least one sealof the invention, combine a particularly advantageous profile ofperformance properties with a particularly long service life, so makingthem particularly valuable economically.

EXAMPLES AND COMPARATIVE EXPERIMENTS Example 1

[0281] The Preparation of an Inventive Polyurethane

[0282] In a reaction vessel equipped with stirrer, internal thermometer,reflux condenser and electrical heating, 701 parts by weight of a linearpolyester polyol (prepared from dimerized fatty acid (Pripol® 1013),isophthalic acid and 1,6-hexanediol) having a hydroxyl number of 80 anda number-average molecular weight of 1400 daltons, 41.5 parts by weightof vinylcyclohexanediol and 99.7 parts by weight of dimethylolpropionicacid were dissolved in 404 parts by weight of methyl ethyl ketone and123 parts by weight of N-methylpyrrolidone. 388.8 parts by weight ofisophorone diisocyanate were added to the resulting solution at 45° C.After the exothermic reaction had subsided, the reaction mixture wasslowly heated to 80° C. with stirring. It was stirred further at thistemperature until the isocyanate content remained constant at 1.1% byweight. The reaction mixture was then cooled to 60° C. and 36.7 parts byweight of diethanolamine were added. The resulting reaction mixture wasstirred at 60° C. until free isocyanate groups were no longerdetectable. The resulting dissolved polyurethane was admixed with 137parts by weight of methoxypropanol and 55 parts by weight oftriethylamine. 30 minutes after adding the amine, 1500 parts by weightof deionized water were added with stirring over the course of 30minutes. The methyl ethyl ketone was removed from the resultingdispersion by distillation under reduced pressure at 60° C. Thereafter,any losses of solvent and of water were compensated. The resultantdispersion of the polyurethane of the invention was adjusted to a solidscontent of 35.1% by weight (one hour at 130° C.) and a pH of 7.3.

Example 2

[0283] The Preparation of an Inventive Primary Dispersion of a GraftCopolymer

[0284] 1487.2 parts by weight of the polyurethane dispersion fromExample 1 were diluted with 864.4 parts by weight of deionized water andheated to 85° C. At this temperature, a mixture of 150.2 parts by weightof styrene, 150.2 parts by weight of methyl methacrylate, 112.4 parts byweight of n-butyl acrylate and 112.4 parts by weight of hydroxyethylmethacrylate were added to the dispersion at a uniform rate over thecourse of 3.5 hours with stirring. At the same time as commencing theaddition of the monomer mixture, a solution of 7.9 parts by weight oftert-butyl peroxyethylhexanoate in 115.5 parts by weight ofmethoxypropanol was added over the course of four hours. The weightratio of polyurethane to monomers was 1:1. The resulting reactionmixture was stirred at 85° C. until all of the monomers had reacted. Theresulting primary dispersion of the graft copolymer had a very goodstorage stability. Its solid content was 35.7% by weight (one hour at130° C.) and its pH was 7.2.

Comparative Experiment Cl

[0285] The Preparation of a Known Polyurethane Containing Lateral VinylGroups

[0286] A hydroxyl-containing polyester was prepared in accordance withpatent EP 0 608 021 A1, page 6 lines 22 to 37 (intermediate A). For thispurpose, a mixture of 236 parts by weight of 1,6-hexanediol, 208 partsby weight of neopentyl glycol, 616 parts by weight of hexahydrophthalicanhydride and 6 parts by weight of benzyltriphenylphosphonium chloridewas charged to an appropriate reaction vessel and heated to 120° C.under nitrogen and with stirring. After one hour at this temperature,the reaction mixture was heated to 140° C. Subsequently, 1000 parts byweight of the glycidyl ester of 1,1-dimethyl-l-heptanecarboxylic acid(Cardura® E-10 from Shell) were metered in over two hours. After fourhours, the reaction mixture had an acid number of 8.5 mg KOH/g. Afurther 80 parts by weight of Cardura® E-10 were added. After anothertwo hours, the acid number of the reaction mixture was less than 1 mgKOH/g.

[0287] In accordance with the instructions given on page 7 lines 1 to 27(Example I) of patent EP 0 608 021 A1, 261.6 parts by weight of theabove-described polyester, 55 parts by weight of N-methylpyrrolidone and0.1 part by weight of dibutyltin diacetate were taken as initial charge.72.1 parts by weight of isophorone diisocyanate were metered into thismixture over the course of one hour at 90° C. After two hours at 90° C.,the reaction mixture was heated to 100° C. At this temperature, 16.3parts by weight of1-(1-isocyanato-1-methylethyl)-3-(1-methylethenyl)benzene (TMI® fromCytec) were metered in over 15 minutes. The resulting reaction mixturewas held at 100° C. for one hour.

[0288] Thereafter, the reaction mixture was heated to 130° C. and atthis temperature a mixture of 38.2 parts by weight of styrene, 9.2 partsby weight of methyl methacrylate, 33.1 parts by weight of acrylic acid,66 parts by weight of Cardura® E-10, 2.7 parts by weight of dicumylperoxide, 0.8 part by weight of 3-mercaptopropionic acid and 51.9 partsby weight of 2-butoxyethanol was added over the course of one hour undernitrogen and with stirring. The resulting reaction mixture was held atthis temperature for three hours. Subsequently, at 115° C., 18.1 partsby weight of dimethylethanolamine were metered in. After the mixture hadcooled to 90° C., 782 parts by weight of deionized water were metered indropwise with stirring over three hours, giving a secondary dispersionhaving a solids content of 35.8% by weight.

Example 3 and Comparative Experiments C2 and C3

[0289] The Preparation of an Inventive Aqueous Basecoat (Example 3) andNoninventive Aqueous Basecoats (Comparative Experiments C2 and C3)

[0290] For the inventive example 3, 9.5 parts by weight of deionizedwater were charged to a mixing vessel. With stirring, 10.5 parts byweight of an aqueous acrylate dispersion [component (i) in accordancewith patent DE 197 36 535 A1; Acronal® 290 D from BASFAktiengesellschaft], 13.5 parts by weight of the inventive primarydispersion of Example 2, 10.4 parts by weight of the thickener 1 (pasteof a synthetic sodium magnesium phyllosilicate from Laporte, 3% inwater), 8.0 parts by weight of deionized water, 0.28 part by weight of a15% strength aqueous ammonia solution and 18.0 parts by weight of athickener 2 (3% strength aqueous solution of a polyacrylic acidthickener from Allied Colloids) were added.

[0291] Subsequently, with stirring, 4.2 parts by weight of a pigmentpaste having a carbon black content of 10% by weight and containing 60%by weight of the acrylated polyurethane dispersion in accordance withExample D of patent DE 44 37 535 A1, 10.2 parts by weight of a fillerpaste having an Aerosil content of 10% by weight and containing 50% byweight of the acrylated polyurethane dispersion in accordance withExample D of patent DE 44 37 535 A1, 2.0 parts by weight of butyl glycoland 3.5 parts by weight of a methanol- and butanol-etherified melamineresin from CYTEC were added.

[0292] In a separate mixing vessel, a mixture of 0.4 part by weight of acommercial aluminum bronze (AluStapa Hydrolux® from Eckart, Al content65% by weight) and 0.6 part by weight of butyl glycol was stirredtogether. This mixture was subsequently added in portions and withvigorous stirring to the other mixture.

[0293] In a further separate mixer, 1.3 parts by weight of a pearlescentpigment (Iriodin® 9103 Sterling Silber WR from Merck) and 2.3 parts byweight of butyl glycol were mixed. This mixture was subsequently addedin portions, again with vigorous stirring, to the mixture describedabove.

[0294] Table 1 gives an overview of the composition of the inventiveaqueous basecoat of Example 3.

[0295] For comparative experiment C2, Example 3 was repeated butreplacing the inventive primary dispersion of Example 2 by the aqueouspolyurethane resin dispersion of Example 1 of patent DE 43 39 870 A1[component (ii)].

[0296] For comparative experiment C3, Example 3 was repeated butreplacing the inventive primary dispersion of Example 2 by the knownsecondary dispersion of comparative experiment C1. The materialcomposition of the noninventive aqueous basecoats C3 and C2 is likewisegiven in Table 1. TABLE 1 The composition of the inventive aqueousbasecoat (Example 3) and of the noninventive aqueous basecoats(comparative experiments C2 and C3) Comparative experiments: Example:Constituents C2 C3 3 Deionized water 9.5 9.5 9.5 Component (i) 10.5 10.510.5 Component (ii) 13.5 — — Secondary — 13.5 — dispersion C1 Primarydispersion — — 13.5 (Ex. 2) Thickener 1 10.4 10.4 10.4 Deionized water8.0 8.0 8.0 Ammonia solution 0.28 0.28 0.28 Thickener 2 18.0 18.0 18.0Pigment paste 4.2 4.2 4.2 Filler paste 10.2 10.2 10.2 Butyl glycol 2.02.0 2.0 Melamine resin 3.5 3.5 3.5 Aluminum paste 0.4 0.4 0.4 Butylglycol 0.6 0.6 0.6 Iriodin 9103 1.3 1.3 1.3 Butyl glycol 2.3 2.3 2.3

[0297] The viscosity of the aqueous basecoats of Table 1 was adjustedusing deionized water to from 90 to 95 mPas at a shear rate of 1000/s.

Example 4 and Comparative Experiments C4 and C5

[0298] The Preparation of an Inventive Multicoat System (Example 4) andof Noninventive Multicoat Systems (Comparative Experiments C4 and C5)

[0299] The inventive multicoat system of Example 4 was prepared usingthe inventive aqueous basecoat of Example 3 (cf. Table 1).

[0300] The noninventive multicoat system of comparative experiment C4was prepared using the noninventive aqueous basecoat of comparativeexperiment C2 (cf. Table 1).

[0301] The noninventive multicoat system of comparative experiment C5was prepared using the noninventive aqueous basecoat of comparativeexperiment C3 (cf. Table 1).

[0302] A. The Preparation of the Test Panels:

[0303] For example 4 and the Comparative experiments C4 and C5, testpanels were first of all prepared. This was done by coating steel panels(bodywork panels), which had been coated with a customary and knowncathodically deposited and baked electrodeposition coating, with acommercial thin-film surfacer (Ecoprime® 60 from BASF Coatings AG;anthracite-colored), after which the resulting surfacer film was flashedoff at 20° C. and a relative atmospheric humidity of 65% for fiveminutes and dried at 80° C. in a convection oven for five minutes.Subsequently, the filler film had a dry film thickness of 15 μm.

[0304] Following the cooling of the test panels to 20° C., the aqueousbasecoats of table 1 were applied, flashed off at 20° C. and a relativeatmospheric humidity of 65% for five minutes and dried at 80° C. in aconvection oven for five minutes, so that the dried basecoat films had adry film thickness of approximately 15 μm.

[0305] After the test panels had again been cooled to 20° C., thebasecoat films were overcoated with a powder slurry clearcoat materialin accordance with International Patent Application WO 96/32452. Theresulting powder slurry clearcoat films were flashed off at 20° C. and arelative atmospheric humidity of 65% for 3 minutes, and dried at 55° C.in a convection oven for five minutes. The dry film thickness of theresulting clearcoat films was from 50 to 60 μm.

[0306] Following the application of all three films, they were bakedjointly at 155° C. for 30 minutes, to give the inventive multicoatsystem of Example 4 and the noninventive multicoat systems of thecomparative experiments C4 and C5.

[0307] B. The Production of Refinish Coats:

[0308] To simulate the refinishing of the entire body on the line (linerefinish), the test panels from Example 4 and from the comparativeexperiments C4 and C5 were sanded with a 1200 grit sandpaper and, inaccordance with the instructions described above, were coated again withthe same multicoat system in each case (double coating). C. TheDetermination of the Popping Limit and Cracking Limit (Mudcracking):

[0309] In accordance with the instructions given in section A. above,multicoat systems were produced in which the basecoats were applied in awedge from 3 to 40 μm. The clearcoats had a coat thickness of from 55 to57 μm. The cracking limit and popping limit indicate the coat thicknessabove which surface defects (in this case popping marks and mudcracking)appear in the clearcoat. The cracking limit and the popping limit are ameasure of the compatibility of the aqueous basecoat material with theclearcoat material, or of the basecoat with the clearcoat; the higherthe cracking limit or the popping limit, the better the compatibility.The corresponding results are given in Table 2.

[0310] D. The Testing of the Clearcoat Adhesion:

[0311] The clearcoat adhesion was tested on unstressed test panels [cf.section A. above (original finish) and section B. above (refinish)]after three days of storage at room temperature. For this purpose, usinga knife or a pointed mandrel, the multicoat systems were scored down tothe steel surface. The score marks were then subjected to a jet of waterunder high pressure for one minute (high-pressure cleaner from Karcher),the water pressure being 230 bar, the water temperature 20° C., and thedistance of the rotating spray nozzle from the test panels 6 cm.Assessment was made visually: if the multicoat system showed no damage,it was assessed as being “satisfactory” (sat.). If delaminationoccurred, this was assessed as being “unsatisfactory” (unsat.). Theresults are likewise given in Table 2.

[0312] E. The Testing of the Intercoat Adhesion After Ball Shot Testing:

[0313] Ball shot testing was carried out in accordance with theDaimlerChrysler specification, which is general knowledge among those inthe art. The corresponding results are likewise given in Table 2.

[0314] F. The Testing of the Intercoat Adhesion After Constant HumidityClimate Exposure to DIN 50017:

[0315] The test panels produced in accordance with the instructionsindicated in section A. were subjected to the constant humidity climateof DIN 50017. Subsequently, after 0 and 2 hours of regeneration, theintercoat adhesion was determined using the cross-cut test in accordancewith DIN EN ISO 2409. The results are likewise given in Table 2. TABLE 2The results of the tests of sections C. to F. Comparative experiments:Example: Tests C4 C5 4 Section C.: Cracking limit (μm): 28 12 36 Poppinglimit (μm) 23 13 29 Section D.: Water jet test: unsat.¹⁾ unsat.¹⁾ sat.Section E.: Ball shot testing: Original finish  6/0 12/0  6/0 Refinish16/0 35/0 14/0 Section F.: Cross-cut test: After 0 hours' GT0 GT3 GT0regeneration After 2 hours' GT0 GT1-2 GT0 regeneration

[0316] The results of Table 2 demonstrate that the inventive aqueousbasecoat of Example 3 and the inventive multicoat system of Example 4were clearly superior to the noninventive aqueous basecoats ofcomparative experiments C2 and C3 and to the noninventive multicoatsystems of comparative experiments C4 and C5 in terms of thecompatibility of aqueous basecoat and powder slurry clearcoat and interms of the intercoat adhesion. Furthermore, they underscore theincompatibility of the noninventive aqueous basecoat C3 with the powderslurry clearcoat and the very poor individual chip resistance of thenoninventive multicoat system C5 produced using it.

[0317] Polyurethanes and Polyurethane-Based Graft Copolymers and TheirUse to Prepare Coating Materials, Adhesives, and Sealing Compounds

What is claimed is:
 1. A hydrophilic or hydrophobic polyurethane havingat least one pendant and/or at least one terminal olefinicallyunsaturated group, in which
 1. the pendant olefinically unsaturatedgroup 1.1 is attached to a cycloaliphatic group which represents a linkin the polymer main chain, or 1.2 is present as a double bond in acycloolefinic group which constitutes a link in the polymer main chain,and
 2. the terminal olefinically unsaturated group 2.1 is attached to acycloaliphatic group which forms an endgroup of the polymer main chain,or 2.2 is present as a double bond in a cycloolefinic structure whichforms an endgroup of the polymer main chain.
 2. The polyurethane asclaimed in claim 1, characterized in that the olefinically unsaturatedgroups attached to the cycloaliphatic groups are (meth)acrylate,ethacrylate, crotonate, cinnamate, vinyl ether, vinyl ester, vinyl,dicyclopentadienyl, norbornenyl, isoprenyl, isopropenyl, allyl and/orbutenyl groups; dicyclopentadienyl ether, norbornenyl ether, isoprenylether, isopropenyl ether, allyl ether or butenyl ether groups; and/ordicyclopentadienyl ester, norbornenyl ester, isoprenyl ester,isopropenyl ester, allyl ester and/or butenyl ester groups.
 3. Thepolyurethane as claimed in claim 2, characterized in that theolefinically unsaturated groups are vinyl groups.
 4. The polyurethane asclaimed in any of claims 1 to 3, characterized in that thecycloaliphatic groups are derived from cycloaliphatics having 4 to 12carbon atoms in the molecule and the cycloolefinic groups are derivedfrom cycloolefins having 4 to 12 carbon atoms in the molecule.
 5. Thepolyurethane as claimed in claim 4, characterized in that thecycloaliphatic groups are derived from cyclobutane, cyclopentane,cyclohexane, cycloheptane, cycloctane, norbornane, bicyclo[2.2.2]octane,decalin, hydroindane, dicylcopentene, tricyclodecane or adamantane andthe cycloolefinic groups are derived from cyclopentene, cyclohexene,cycloheptene, cyclooctene, norbornene, bicyclo[2.2.2]octene ordicylclopentene.
 6. The polyurethane as claimed in any of claims 1 to 5,characterized in that it is preparable by reacting (i) at least onepolyurethane prepolymer having at least one free isocyanate group in themolecule with (ii) at least one cycloaliphatic having at least oneolefinically unsaturated group and having at least twoisocyanate-reactive groups in the molecule, and/or with (iii) at leastone cycloolefin having at least two isocyanate-reactive groups in themolecule.
 7. The polyurethane as claimed in claim 6, characterized inthat the cycloaliphatics (ii) and/or cycloolefins (iii) contain twoisocyanate-reactive groups in the molecule.
 8. The polyurethane asclaimed in claim 6 or 7, characterized in that isocyanate-reactivegroups used comprise hydroxyl, thiol and/or primary and/or secondaryamino groups.
 9. The polyurethane as claimed in claim 8, characterizedin that hydroxyl groups are used.
 10. The polyurethane as claimed in anyof claims 6 to 9, characterized in that the cycloaliphatics (ii)comprise an olefinically unsaturated group.
 11. The polyurethane asclaimed in any of claims 6 to 10, characterized in that olefinicallyunsaturated groups used comprise (meth)acrylate, ethacrylate, crotonate,cinnamate, vinyl ether, vinyl ester, vinyl, dicyclopentadienyl,norbornenyl, isoprenyl, isopropenyl, allyl and/or butenyl groups;dicyclopentadienyl ether, norbornenyl ether, isoprenyl ether,isopropenyl ether, allyl ether or butenyl ether groups; and/ordicyclopentadienyl ester, norbornenyl ester, isoprenyl ester,isopropenyl ester, allyl ester and/or butenyl ester groups.
 12. Thepolyurethane as claimed in claim 11, characterized in that vinyl groupsare used.
 13. The polyurethane as claimed in claim 12, characterized inthat cycloaliphatics (ii) used comprise the positionally isomericvinyl-substituted polyhydroxy derivatives of cyclobutane, cyclopentane,cyclohexane, cycloheptane, cycloctane, norbornane, bicyclo[2.2.2]octane,decalin, hydroindane, dicylcopentene, tricyclodecane or adamantane andthe cycloolefins (iii) used comprise the positionally isomericpolyhydroxy derivatives of cyclopentene, cyclohexene, cycloheptene,cyclooctene, norbornene, bicyclo[2.2.2]octene or dicylclopentene. 14.The polyurethane as claimed in claim 13, characterized in that thepositionally isomeric dihydroxy derivatives are used.
 15. Thepolyurethane as claimed in claim 14, characterized in thatvinylcyclohexanediol is used.
 16. The polyurethane as claimed in any ofclaims 1 to 15, characterized in that the polyurethane prepolymer isprepared from at least one diisocyanate and at least one compound havingtwo isocyanate-reactive groups.
 17. A graft copolymer preparable by(co)polymerizing at least one monomer (a) in the presence of at leastone polyurethane as claimed in any of claims 1 to
 16. 18. The use of apolyurethane as claimed in any of claims 1 to 16 and/or of a graftcopolymer as claimed in claim 17 to prepare a sealing compound,adhesive, or coating material.
 19. A sealing compound, adhesive, orcoating material characterized in that it comprises at least onepolyurethane as claimed in any of claims 1 to 16 and/or at least onegraft copolymer as claimed in claim 17.